update windows build to Python 3.7

2019-01-20 16:05:31 +05:30 · 2019-01-20 16:05:31 +05:30 · ddc59ab92d
commit ddc59ab92d
parent 73105fa71e
5761 changed files with 750298 additions and 213405 deletions
--- a/.gitignore
+++ b/.gitignore
@ -1,8 +0,0 @@
 *.swp
 *.pyc
 *.pyo
 __pycache__
 pip_cache
 .DS_Store
 build
 dist
--- a/339
+++ b/339
@ -1,339 +0,0 @@
 		    GNU GENERAL PUBLIC LICENSE
 		       Version 2, June 1991
 Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.
 			    Preamble
  The licenses for most software are designed to take away your
 freedom to share and change it.  By contrast, the GNU General Public
 License is intended to guarantee your freedom to share and change free
 software--to make sure the software is free for all its users.  This
 General Public License applies to most of the Free Software
 Foundation's software and to any other program whose authors commit to
 using it.  (Some other Free Software Foundation software is covered by
 the GNU Lesser General Public License instead.)  You can apply it to
 your programs, too.
  When we speak of free software, we are referring to freedom, not
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  To protect your rights, we need to make restrictions that forbid
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 		    GNU GENERAL PUBLIC LICENSE
   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
  0. This License applies to any program or other work which contains
 a notice placed by the copyright holder saying it may be distributed
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 			    NO WARRANTY
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 FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
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 		     END OF TERMS AND CONDITIONS
 	    How to Apply These Terms to Your New Programs
  If you develop a new program, and you want it to be of the greatest
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    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>
    This program is free software; you can redistribute it and/or modify
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    (at your option) any later version.
    This program is distributed in the hope that it will be useful,
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 Also add information on how to contact you by electronic and paper mail.
 If the program is interactive, make it output a short notice like this
 when it starts in an interactive mode:
    Gnomovision version 69, Copyright (C) year name of author
    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details.
 The hypothetical commands `show w' and `show c' should show the appropriate
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 be called something other than `show w' and `show c'; they could even be
 mouse-clicks or menu items--whatever suits your program.
 You should also get your employer (if you work as a programmer) or your
 school, if any, to sign a "copyright disclaimer" for the program, if
 necessary.  Here is a sample; alter the names:
  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
  `Gnomovision' (which makes passes at compilers) written by James Hacker.
  <signature of Ty Coon>, 1 April 1989
  Ty Coon, President of Vice
 This General Public License does not permit incorporating your program into
 proprietary programs.  If your program is a subroutine library, you may
 consider it more useful to permit linking proprietary applications with the
 library.  If this is what you want to do, use the GNU Lesser General
 Public License instead of this License.
--- a/674
+++ b/674
@ -1,674 +0,0 @@
                    GNU GENERAL PUBLIC LICENSE
                       Version 3, 29 June 2007
 Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.
                            Preamble
  The GNU General Public License is a free, copyleft license for
 software and other kinds of works.
  The licenses for most software and other practical works are designed
 to take away your freedom to share and change the works.  By contrast,
 the GNU General Public License is intended to guarantee your freedom to
 share and change all versions of a program--to make sure it remains free
 software for all its users.  We, the Free Software Foundation, use the
 GNU General Public License for most of our software; it applies also to
 any other work released this way by its authors.  You can apply it to
 your programs, too.
  When we speak of free software, we are referring to freedom, not
 price.  Our General Public Licenses are designed to make sure that you
 have the freedom to distribute copies of free software (and charge for
 them if you wish), that you receive source code or can get it if you
 want it, that you can change the software or use pieces of it in new
 free programs, and that you know you can do these things.
  To protect your rights, we need to prevent others from denying you
 these rights or asking you to surrender the rights.  Therefore, you have
 certain responsibilities if you distribute copies of the software, or if
 you modify it: responsibilities to respect the freedom of others.
  For example, if you distribute copies of such a program, whether
 gratis or for a fee, you must pass on to the recipients the same
 freedoms that you received.  You must make sure that they, too, receive
 or can get the source code.  And you must show them these terms so they
 know their rights.
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 and execute modified versions of a covered work in that User Product from
 a modified version of its Corresponding Source.  The information must
 suffice to ensure that the continued functioning of the modified object
 code is in no case prevented or interfered with solely because
 modification has been made.
  If you convey an object code work under this section in, or with, or
 specifically for use in, a User Product, and the conveying occurs as
 part of a transaction in which the right of possession and use of the
 User Product is transferred to the recipient in perpetuity or for a
 fixed term (regardless of how the transaction is characterized), the
 Corresponding Source conveyed under this section must be accompanied
 by the Installation Information.  But this requirement does not apply
 if neither you nor any third party retains the ability to install
 modified object code on the User Product (for example, the work has
 been installed in ROM).
  The requirement to provide Installation Information does not include a
 requirement to continue to provide support service, warranty, or updates
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 the User Product in which it has been modified or installed.  Access to a
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  Corresponding Source conveyed, and Installation Information provided,
 in accord with this section must be in a format that is publicly
 documented (and with an implementation available to the public in
 source code form), and must require no special password or key for
 unpacking, reading or copying.
  7. Additional Terms.
  "Additional permissions" are terms that supplement the terms of this
 License by making exceptions from one or more of its conditions.
 Additional permissions that are applicable to the entire Program shall
 be treated as though they were included in this License, to the extent
 that they are valid under applicable law.  If additional permissions
 apply only to part of the Program, that part may be used separately
 under those permissions, but the entire Program remains governed by
 this License without regard to the additional permissions.
  When you convey a copy of a covered work, you may at your option
 remove any additional permissions from that copy, or from any part of
 it.  (Additional permissions may be written to require their own
 removal in certain cases when you modify the work.)  You may place
 additional permissions on material, added by you to a covered work,
 for which you have or can give appropriate copyright permission.
  Notwithstanding any other provision of this License, for material you
 add to a covered work, you may (if authorized by the copyright holders of
 that material) supplement the terms of this License with terms:
    a) Disclaiming warranty or limiting liability differently from the
    terms of sections 15 and 16 of this License; or
    b) Requiring preservation of specified reasonable legal notices or
    author attributions in that material or in the Appropriate Legal
    Notices displayed by works containing it; or
    c) Prohibiting misrepresentation of the origin of that material, or
    requiring that modified versions of such material be marked in
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    d) Limiting the use for publicity purposes of names of licensors or
    authors of the material; or
    e) Declining to grant rights under trademark law for use of some
    trade names, trademarks, or service marks; or
    f) Requiring indemnification of licensors and authors of that
    material by anyone who conveys the material (or modified versions of
    it) with contractual assumptions of liability to the recipient, for
    any liability that these contractual assumptions directly impose on
    those licensors and authors.
  All other non-permissive additional terms are considered "further
 restrictions" within the meaning of section 10.  If the Program as you
 received it, or any part of it, contains a notice stating that it is
 governed by this License along with a term that is a further
 restriction, you may remove that term.  If a license document contains
 a further restriction but permits relicensing or conveying under this
 License, you may add to a covered work material governed by the terms
 of that license document, provided that the further restriction does
 not survive such relicensing or conveying.
  If you add terms to a covered work in accord with this section, you
 must place, in the relevant source files, a statement of the
 additional terms that apply to those files, or a notice indicating
 where to find the applicable terms.
  Additional terms, permissive or non-permissive, may be stated in the
 form of a separately written license, or stated as exceptions;
 the above requirements apply either way.
  8. Termination.
  You may not propagate or modify a covered work except as expressly
 provided under this License.  Any attempt otherwise to propagate or
 modify it is void, and will automatically terminate your rights under
 this License (including any patent licenses granted under the third
 paragraph of section 11).
  However, if you cease all violation of this License, then your
 license from a particular copyright holder is reinstated (a)
 provisionally, unless and until the copyright holder explicitly and
 finally terminates your license, and (b) permanently, if the copyright
 holder fails to notify you of the violation by some reasonable means
 prior to 60 days after the cessation.
  Moreover, your license from a particular copyright holder is
 reinstated permanently if the copyright holder notifies you of the
 violation by some reasonable means, this is the first time you have
 received notice of violation of this License (for any work) from that
 copyright holder, and you cure the violation prior to 30 days after
 your receipt of the notice.
  Termination of your rights under this section does not terminate the
 licenses of parties who have received copies or rights from you under
 this License.  If your rights have been terminated and not permanently
 reinstated, you do not qualify to receive new licenses for the same
 material under section 10.
  9. Acceptance Not Required for Having Copies.
  You are not required to accept this License in order to receive or
 run a copy of the Program.  Ancillary propagation of a covered work
 occurring solely as a consequence of using peer-to-peer transmission
 to receive a copy likewise does not require acceptance.  However,
 nothing other than this License grants you permission to propagate or
 modify any covered work.  These actions infringe copyright if you do
 not accept this License.  Therefore, by modifying or propagating a
 covered work, you indicate your acceptance of this License to do so.
  10. Automatic Licensing of Downstream Recipients.
  Each time you convey a covered work, the recipient automatically
 receives a license from the original licensors, to run, modify and
 propagate that work, subject to this License.  You are not responsible
 for enforcing compliance by third parties with this License.
  An "entity transaction" is a transaction transferring control of an
 organization, or substantially all assets of one, or subdividing an
 organization, or merging organizations.  If propagation of a covered
 work results from an entity transaction, each party to that
 transaction who receives a copy of the work also receives whatever
 licenses to the work the party's predecessor in interest had or could
 give under the previous paragraph, plus a right to possession of the
 Corresponding Source of the work from the predecessor in interest, if
 the predecessor has it or can get it with reasonable efforts.
  You may not impose any further restrictions on the exercise of the
 rights granted or affirmed under this License.  For example, you may
 not impose a license fee, royalty, or other charge for exercise of
 rights granted under this License, and you may not initiate litigation
 (including a cross-claim or counterclaim in a lawsuit) alleging that
 any patent claim is infringed by making, using, selling, offering for
 sale, or importing the Program or any portion of it.
  11. Patents.
  A "contributor" is a copyright holder who authorizes use under this
 License of the Program or a work on which the Program is based.  The
 work thus licensed is called the contributor's "contributor version".
  A contributor's "essential patent claims" are all patent claims
 owned or controlled by the contributor, whether already acquired or
 hereafter acquired, that would be infringed by some manner, permitted
 by this License, of making, using, or selling its contributor version,
 but do not include claims that would be infringed only as a
 consequence of further modification of the contributor version.  For
 purposes of this definition, "control" includes the right to grant
 patent sublicenses in a manner consistent with the requirements of
 this License.
  Each contributor grants you a non-exclusive, worldwide, royalty-free
 patent license under the contributor's essential patent claims, to
 make, use, sell, offer for sale, import and otherwise run, modify and
 propagate the contents of its contributor version.
  In the following three paragraphs, a "patent license" is any express
 agreement or commitment, however denominated, not to enforce a patent
 (such as an express permission to practice a patent or covenant not to
 sue for patent infringement).  To "grant" such a patent license to a
 party means to make such an agreement or commitment not to enforce a
 patent against the party.
  If you convey a covered work, knowingly relying on a patent license,
 and the Corresponding Source of the work is not available for anyone
 to copy, free of charge and under the terms of this License, through a
 publicly available network server or other readily accessible means,
 then you must either (1) cause the Corresponding Source to be so
 available, or (2) arrange to deprive yourself of the benefit of the
 patent license for this particular work, or (3) arrange, in a manner
 consistent with the requirements of this License, to extend the patent
 license to downstream recipients.  "Knowingly relying" means you have
 actual knowledge that, but for the patent license, your conveying the
 covered work in a country, or your recipient's use of the covered work
 in a country, would infringe one or more identifiable patents in that
 country that you have reason to believe are valid.
  If, pursuant to or in connection with a single transaction or
 arrangement, you convey, or propagate by procuring conveyance of, a
 covered work, and grant a patent license to some of the parties
 receiving the covered work authorizing them to use, propagate, modify
 or convey a specific copy of the covered work, then the patent license
 you grant is automatically extended to all recipients of the covered
 work and works based on it.
  A patent license is "discriminatory" if it does not include within
 the scope of its coverage, prohibits the exercise of, or is
 conditioned on the non-exercise of one or more of the rights that are
 specifically granted under this License.  You may not convey a covered
 work if you are a party to an arrangement with a third party that is
 in the business of distributing software, under which you make payment
 to the third party based on the extent of your activity of conveying
 the work, and under which the third party grants, to any of the
 parties who would receive the covered work from you, a discriminatory
 patent license (a) in connection with copies of the covered work
 conveyed by you (or copies made from those copies), or (b) primarily
 for and in connection with specific products or compilations that
 contain the covered work, unless you entered into that arrangement,
 or that patent license was granted, prior to 28 March 2007.
  Nothing in this License shall be construed as excluding or limiting
 any implied license or other defenses to infringement that may
 otherwise be available to you under applicable patent law.
  12. No Surrender of Others' Freedom.
  If conditions are imposed on you (whether by court order, agreement or
 otherwise) that contradict the conditions of this License, they do not
 excuse you from the conditions of this License.  If you cannot convey a
 covered work so as to satisfy simultaneously your obligations under this
 License and any other pertinent obligations, then as a consequence you may
 not convey it at all.  For example, if you agree to terms that obligate you
 to collect a royalty for further conveying from those to whom you convey
 the Program, the only way you could satisfy both those terms and this
 License would be to refrain entirely from conveying the Program.
  13. Use with the GNU Affero General Public License.
  Notwithstanding any other provision of this License, you have
 permission to link or combine any covered work with a work licensed
 under version 3 of the GNU Affero General Public License into a single
 combined work, and to convey the resulting work.  The terms of this
 License will continue to apply to the part which is the covered work,
 but the special requirements of the GNU Affero General Public License,
 section 13, concerning interaction through a network will apply to the
 combination as such.
  14. Revised Versions of this License.
  The Free Software Foundation may publish revised and/or new versions of
 the GNU General Public License from time to time.  Such new versions will
 be similar in spirit to the present version, but may differ in detail to
 address new problems or concerns.
  Each version is given a distinguishing version number.  If the
 Program specifies that a certain numbered version of the GNU General
 Public License "or any later version" applies to it, you have the
 option of following the terms and conditions either of that numbered
 version or of any later version published by the Free Software
 Foundation.  If the Program does not specify a version number of the
 GNU General Public License, you may choose any version ever published
 by the Free Software Foundation.
  If the Program specifies that a proxy can decide which future
 versions of the GNU General Public License can be used, that proxy's
 public statement of acceptance of a version permanently authorizes you
 to choose that version for the Program.
  Later license versions may give you additional or different
 permissions.  However, no additional obligations are imposed on any
 author or copyright holder as a result of your choosing to follow a
 later version.
  15. Disclaimer of Warranty.
  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
 APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
 HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
 OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
 THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
 IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
 ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
  16. Limitation of Liability.
  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
 WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
 THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
 GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
 USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
 DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
 PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
 EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
 SUCH DAMAGES.
  17. Interpretation of Sections 15 and 16.
  If the disclaimer of warranty and limitation of liability provided
 above cannot be given local legal effect according to their terms,
 reviewing courts shall apply local law that most closely approximates
 an absolute waiver of all civil liability in connection with the
 Program, unless a warranty or assumption of liability accompanies a
 copy of the Program in return for a fee.
                     END OF TERMS AND CONDITIONS
            How to Apply These Terms to Your New Programs
  If you develop a new program, and you want it to be of the greatest
 possible use to the public, the best way to achieve this is to make it
 free software which everyone can redistribute and change under these terms.
  To do so, attach the following notices to the program.  It is safest
 to attach them to the start of each source file to most effectively
 state the exclusion of warranty; and each file should have at least
 the "copyright" line and a pointer to where the full notice is found.
    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 Also add information on how to contact you by electronic and paper mail.
  If the program does terminal interaction, make it output a short
 notice like this when it starts in an interactive mode:
    <program>  Copyright (C) <year>  <name of author>
    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details.
 The hypothetical commands `show w' and `show c' should show the appropriate
 parts of the General Public License.  Of course, your program's commands
 might be different; for a GUI interface, you would use an "about box".
  You should also get your employer (if you work as a programmer) or school,
 if any, to sign a "copyright disclaimer" for the program, if necessary.
 For more information on this, and how to apply and follow the GNU GPL, see
 <http://www.gnu.org/licenses/>.
  The GNU General Public License does not permit incorporating your program
 into proprietary programs.  If your program is a subroutine library, you
 may consider it more useful to permit linking proprietary applications with
 the library.  If this is what you want to do, use the GNU Lesser General
 Public License instead of this License.  But first, please read
 <http://www.gnu.org/philosophy/why-not-lgpl.html>.
--- a/DLLs/_asyncio.pyd
+++ b/DLLs/_asyncio.pyd
--- a/DLLs/_bz2.pyd
+++ b/DLLs/_bz2.pyd
--- a/DLLs/_contextvars.pyd
+++ b/DLLs/_contextvars.pyd
--- a/DLLs/_ctypes.pyd
+++ b/DLLs/_ctypes.pyd
--- a/DLLs/_ctypes_test.pyd
+++ b/DLLs/_ctypes_test.pyd
--- a/DLLs/_decimal.pyd
+++ b/DLLs/_decimal.pyd
--- a/DLLs/_elementtree.pyd
+++ b/DLLs/_elementtree.pyd
--- a/DLLs/_hashlib.pyd
+++ b/DLLs/_hashlib.pyd
--- a/DLLs/_lzma.pyd
+++ b/DLLs/_lzma.pyd
--- a/DLLs/_msi.pyd
+++ b/DLLs/_msi.pyd
--- a/DLLs/_multiprocessing.pyd
+++ b/DLLs/_multiprocessing.pyd
--- a/DLLs/_overlapped.pyd
+++ b/DLLs/_overlapped.pyd
--- a/DLLs/_queue.pyd
+++ b/DLLs/_queue.pyd
--- a/DLLs/_socket.pyd
+++ b/DLLs/_socket.pyd
--- a/DLLs/_sqlite3.pyd
+++ b/DLLs/_sqlite3.pyd
--- a/DLLs/_ssl.pyd
+++ b/DLLs/_ssl.pyd
--- a/DLLs/_testbuffer.pyd
+++ b/DLLs/_testbuffer.pyd
--- a/DLLs/_testcapi.pyd
+++ b/DLLs/_testcapi.pyd
--- a/DLLs/_testconsole.pyd
+++ b/DLLs/_testconsole.pyd
--- a/DLLs/_testimportmultiple.pyd
+++ b/DLLs/_testimportmultiple.pyd
--- a/DLLs/_testmultiphase.pyd
+++ b/DLLs/_testmultiphase.pyd
--- a/DLLs/_tkinter.pyd
+++ b/DLLs/_tkinter.pyd
--- a/DLLs/libcrypto-1_1-x64.dll
+++ b/DLLs/libcrypto-1_1-x64.dll
--- a/DLLs/libssl-1_1-x64.dll
+++ b/DLLs/libssl-1_1-x64.dll
--- a/DLLs/py.ico
+++ b/DLLs/py.ico
--- a/DLLs/pyc.ico
+++ b/DLLs/pyc.ico
--- a/DLLs/pyd.ico
+++ b/DLLs/pyd.ico
--- a/DLLs/pyexpat.pyd
+++ b/DLLs/pyexpat.pyd
--- a/DLLs/python_lib.cat
+++ b/DLLs/python_lib.cat
--- a/DLLs/python_tools.cat
+++ b/DLLs/python_tools.cat
--- a/DLLs/select.pyd
+++ b/DLLs/select.pyd
--- a/DLLs/sqlite3.dll
+++ b/DLLs/sqlite3.dll
--- a/DLLs/tcl86t.dll
+++ b/DLLs/tcl86t.dll
--- a/DLLs/tk86t.dll
+++ b/DLLs/tk86t.dll
--- a/DLLs/unicodedata.pyd
+++ b/DLLs/unicodedata.pyd
--- a/DLLs/winsound.pyd
+++ b/DLLs/winsound.pyd
--- a/LICENSE.txt
+++ b/LICENSE.txt
@ -0,0 +1,603 @@
 A. HISTORY OF THE SOFTWARE
 ==========================
 Python was created in the early 1990s by Guido van Rossum at Stichting
 Mathematisch Centrum (CWI, see http://www.cwi.nl) in the Netherlands
 as a successor of a language called ABC.  Guido remains Python's
 principal author, although it includes many contributions from others.
 In 1995, Guido continued his work on Python at the Corporation for
 National Research Initiatives (CNRI, see http://www.cnri.reston.va.us)
 in Reston, Virginia where he released several versions of the
 software.
 In May 2000, Guido and the Python core development team moved to
 BeOpen.com to form the BeOpen PythonLabs team.  In October of the same
 year, the PythonLabs team moved to Digital Creations, which became
 Zope Corporation.  In 2001, the Python Software Foundation (PSF, see
 https://www.python.org/psf/) was formed, a non-profit organization
 created specifically to own Python-related Intellectual Property.
 Zope Corporation was a sponsoring member of the PSF.
 All Python releases are Open Source (see http://www.opensource.org for
 the Open Source Definition).  Historically, most, but not all, Python
 releases have also been GPL-compatible; the table below summarizes
 the various releases.
    Release         Derived     Year        Owner       GPL-
                    from                                compatible? (1)
    0.9.0 thru 1.2              1991-1995   CWI         yes
    1.3 thru 1.5.2  1.2         1995-1999   CNRI        yes
    1.6             1.5.2       2000        CNRI        no
    2.0             1.6         2000        BeOpen.com  no
    1.6.1           1.6         2001        CNRI        yes (2)
    2.1             2.0+1.6.1   2001        PSF         no
    2.0.1           2.0+1.6.1   2001        PSF         yes
    2.1.1           2.1+2.0.1   2001        PSF         yes
    2.1.2           2.1.1       2002        PSF         yes
    2.1.3           2.1.2       2002        PSF         yes
    2.2 and above   2.1.1       2001-now    PSF         yes
 Footnotes:
 (1) GPL-compatible doesn't mean that we're distributing Python under
    the GPL.  All Python licenses, unlike the GPL, let you distribute
    a modified version without making your changes open source.  The
    GPL-compatible licenses make it possible to combine Python with
    other software that is released under the GPL; the others don't.
 (2) According to Richard Stallman, 1.6.1 is not GPL-compatible,
    because its license has a choice of law clause.  According to
    CNRI, however, Stallman's lawyer has told CNRI's lawyer that 1.6.1
    is "not incompatible" with the GPL.
 Thanks to the many outside volunteers who have worked under Guido's
 direction to make these releases possible.
 B. TERMS AND CONDITIONS FOR ACCESSING OR OTHERWISE USING PYTHON
 ===============================================================
 PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2
 --------------------------------------------
 1. This LICENSE AGREEMENT is between the Python Software Foundation
 ("PSF"), and the Individual or Organization ("Licensee") accessing and
 otherwise using this software ("Python") in source or binary form and
 its associated documentation.
 2. Subject to the terms and conditions of this License Agreement, PSF hereby
 grants Licensee a nonexclusive, royalty-free, world-wide license to reproduce,
 analyze, test, perform and/or display publicly, prepare derivative works,
 distribute, and otherwise use Python alone or in any derivative version,
 provided, however, that PSF's License Agreement and PSF's notice of copyright,
 i.e., "Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018 Python Software Foundation; All
 Rights Reserved" are retained in Python alone or in any derivative version
 prepared by Licensee.
 3. In the event Licensee prepares a derivative work that is based on
 or incorporates Python or any part thereof, and wants to make
 the derivative work available to others as provided herein, then
 Licensee hereby agrees to include in any such work a brief summary of
 the changes made to Python.
 4. PSF is making Python available to Licensee on an "AS IS"
 basis.  PSF MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR
 IMPLIED.  BY WAY OF EXAMPLE, BUT NOT LIMITATION, PSF MAKES NO AND
 DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS
 FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF PYTHON WILL NOT
 INFRINGE ANY THIRD PARTY RIGHTS.
 5. PSF SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON
 FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS
 A RESULT OF MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON,
 OR ANY DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.
 6. This License Agreement will automatically terminate upon a material
 breach of its terms and conditions.
 7. Nothing in this License Agreement shall be deemed to create any
 relationship of agency, partnership, or joint venture between PSF and
 Licensee.  This License Agreement does not grant permission to use PSF
 trademarks or trade name in a trademark sense to endorse or promote
 products or services of Licensee, or any third party.
 8. By copying, installing or otherwise using Python, Licensee
 agrees to be bound by the terms and conditions of this License
 Agreement.
 BEOPEN.COM LICENSE AGREEMENT FOR PYTHON 2.0
 -------------------------------------------
 BEOPEN PYTHON OPEN SOURCE LICENSE AGREEMENT VERSION 1
 1. This LICENSE AGREEMENT is between BeOpen.com ("BeOpen"), having an
 office at 160 Saratoga Avenue, Santa Clara, CA 95051, and the
 Individual or Organization ("Licensee") accessing and otherwise using
 this software in source or binary form and its associated
 documentation ("the Software").
 2. Subject to the terms and conditions of this BeOpen Python License
 Agreement, BeOpen hereby grants Licensee a non-exclusive,
 royalty-free, world-wide license to reproduce, analyze, test, perform
 and/or display publicly, prepare derivative works, distribute, and
 otherwise use the Software alone or in any derivative version,
 provided, however, that the BeOpen Python License is retained in the
 Software, alone or in any derivative version prepared by Licensee.
 3. BeOpen is making the Software available to Licensee on an "AS IS"
 basis.  BEOPEN MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR
 IMPLIED.  BY WAY OF EXAMPLE, BUT NOT LIMITATION, BEOPEN MAKES NO AND
 DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS
 FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF THE SOFTWARE WILL NOT
 INFRINGE ANY THIRD PARTY RIGHTS.
 4. BEOPEN SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF THE
 SOFTWARE FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS
 AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THE SOFTWARE, OR ANY
 DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.
 5. This License Agreement will automatically terminate upon a material
 breach of its terms and conditions.
 6. This License Agreement shall be governed by and interpreted in all
 respects by the law of the State of California, excluding conflict of
 law provisions.  Nothing in this License Agreement shall be deemed to
 create any relationship of agency, partnership, or joint venture
 between BeOpen and Licensee.  This License Agreement does not grant
 permission to use BeOpen trademarks or trade names in a trademark
 sense to endorse or promote products or services of Licensee, or any
 third party.  As an exception, the "BeOpen Python" logos available at
 http://www.pythonlabs.com/logos.html may be used according to the
 permissions granted on that web page.
 7. By copying, installing or otherwise using the software, Licensee
 agrees to be bound by the terms and conditions of this License
 Agreement.
 CNRI LICENSE AGREEMENT FOR PYTHON 1.6.1
 ---------------------------------------
 1. This LICENSE AGREEMENT is between the Corporation for National
 Research Initiatives, having an office at 1895 Preston White Drive,
 Reston, VA 20191 ("CNRI"), and the Individual or Organization
 ("Licensee") accessing and otherwise using Python 1.6.1 software in
 source or binary form and its associated documentation.
 2. Subject to the terms and conditions of this License Agreement, CNRI
 hereby grants Licensee a nonexclusive, royalty-free, world-wide
 license to reproduce, analyze, test, perform and/or display publicly,
 prepare derivative works, distribute, and otherwise use Python 1.6.1
 alone or in any derivative version, provided, however, that CNRI's
 License Agreement and CNRI's notice of copyright, i.e., "Copyright (c)
 1995-2001 Corporation for National Research Initiatives; All Rights
 Reserved" are retained in Python 1.6.1 alone or in any derivative
 version prepared by Licensee.  Alternately, in lieu of CNRI's License
 Agreement, Licensee may substitute the following text (omitting the
 quotes): "Python 1.6.1 is made available subject to the terms and
 conditions in CNRI's License Agreement.  This Agreement together with
 Python 1.6.1 may be located on the Internet using the following
 unique, persistent identifier (known as a handle): 1895.22/1013.  This
 Agreement may also be obtained from a proxy server on the Internet
 using the following URL: http://hdl.handle.net/1895.22/1013".
 3. In the event Licensee prepares a derivative work that is based on
 or incorporates Python 1.6.1 or any part thereof, and wants to make
 the derivative work available to others as provided herein, then
 Licensee hereby agrees to include in any such work a brief summary of
 the changes made to Python 1.6.1.
 4. CNRI is making Python 1.6.1 available to Licensee on an "AS IS"
 basis.  CNRI MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR
 IMPLIED.  BY WAY OF EXAMPLE, BUT NOT LIMITATION, CNRI MAKES NO AND
 DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS
 FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF PYTHON 1.6.1 WILL NOT
 INFRINGE ANY THIRD PARTY RIGHTS.
 5. CNRI SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON
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 Notwithstanding the foregoing, with regard to derivative works based
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        ACCEPT
 CWI LICENSE AGREEMENT FOR PYTHON 0.9.0 THROUGH 1.2
 --------------------------------------------------
 Copyright (c) 1991 - 1995, Stichting Mathematisch Centrum Amsterdam,
 The Netherlands.  All rights reserved.
 Permission to use, copy, modify, and distribute this software and its
 documentation for any purpose and without fee is hereby granted,
 provided that the above copyright notice appear in all copies and that
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 ---------------------------------------------------
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 is embedded in each .exe, .dll and .pyd file as a result of running
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 If you further distribute programs that include the Microsoft
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 Redistribution of the Windows binary build of the Python interpreter
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 --------------------------------------------------------------------------
 This program, "bzip2", the associated library "libbzip2", and all
 documentation, are copyright (C) 1996-2010 Julian R Seward.  All
 rights reserved.
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions
 are met:
 1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
 2. The origin of this software must not be misrepresented; you must 
   not claim that you wrote the original software.  If you use this 
   software in a product, an acknowledgment in the product 
   documentation would be appreciated but is not required.
 3. Altered source versions must be plainly marked as such, and must
   not be misrepresented as being the original software.
 4. The name of the author may not be used to endorse or promote 
   products derived from this software without specific prior written 
   permission.
 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
 OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 Julian Seward, jseward@bzip.org
 bzip2/libbzip2 version 1.0.6 of 6 September 2010
 --------------------------------------------------------------------------
  LICENSE ISSUES
  ==============
  The OpenSSL toolkit stays under a double license, i.e. both the conditions of
  the OpenSSL License and the original SSLeay license apply to the toolkit.
  See below for the actual license texts.
  OpenSSL License
  ---------------
 /* ====================================================================
 * Copyright (c) 1998-2018 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */
 Original SSLeay License
 -----------------------
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 * 
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from 
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */
 This software is copyrighted by the Regents of the University of
 California, Sun Microsystems, Inc., Scriptics Corporation, ActiveState
 Corporation and other parties.  The following terms apply to all files
 associated with the software unless explicitly disclaimed in
 individual files.
 The authors hereby grant permission to use, copy, modify, distribute,
 and license this software and its documentation for any purpose, provided
 that existing copyright notices are retained in all copies and that this
 notice is included verbatim in any distributions. No written agreement,
 license, or royalty fee is required for any of the authorized uses.
 Modifications to this software may be copyrighted by their authors
 and need not follow the licensing terms described here, provided that
 the new terms are clearly indicated on the first page of each file where
 they apply.
 IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY
 FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 ARISING OUT OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION, OR ANY
 DERIVATIVES THEREOF, EVEN IF THE AUTHORS HAVE BEEN ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
 THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES,
 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT.  THIS SOFTWARE
 IS PROVIDED ON AN "AS IS" BASIS, AND THE AUTHORS AND DISTRIBUTORS HAVE
 NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR
 MODIFICATIONS.
 GOVERNMENT USE: If you are acquiring this software on behalf of the
 U.S. government, the Government shall have only "Restricted Rights"
 in the software and related documentation as defined in the Federal
 Acquisition Regulations (FARs) in Clause 52.227.19 (c) (2).  If you
 are acquiring the software on behalf of the Department of Defense, the
 software shall be classified as "Commercial Computer Software" and the
 Government shall have only "Restricted Rights" as defined in Clause
 252.227-7014 (b) (3) of DFARs.  Notwithstanding the foregoing, the
 authors grant the U.S. Government and others acting in its behalf
 permission to use and distribute the software in accordance with the
 terms specified in this license.
 This software is copyrighted by the Regents of the University of
 California, Sun Microsystems, Inc., Scriptics Corporation, ActiveState
 Corporation, Apple Inc. and other parties.  The following terms apply to
 all files associated with the software unless explicitly disclaimed in
 individual files.
 The authors hereby grant permission to use, copy, modify, distribute,
 and license this software and its documentation for any purpose, provided
 that existing copyright notices are retained in all copies and that this
 notice is included verbatim in any distributions. No written agreement,
 license, or royalty fee is required for any of the authorized uses.
 Modifications to this software may be copyrighted by their authors
 and need not follow the licensing terms described here, provided that
 the new terms are clearly indicated on the first page of each file where
 they apply.
 IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY
 FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 ARISING OUT OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION, OR ANY
 DERIVATIVES THEREOF, EVEN IF THE AUTHORS HAVE BEEN ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
 THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES,
 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT.  THIS SOFTWARE
 IS PROVIDED ON AN "AS IS" BASIS, AND THE AUTHORS AND DISTRIBUTORS HAVE
 NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR
 MODIFICATIONS.
 GOVERNMENT USE: If you are acquiring this software on behalf of the
 U.S. government, the Government shall have only "Restricted Rights"
 in the software and related documentation as defined in the Federal
 Acquisition Regulations (FARs) in Clause 52.227.19 (c) (2).  If you
 are acquiring the software on behalf of the Department of Defense, the
 software shall be classified as "Commercial Computer Software" and the
 Government shall have only "Restricted Rights" as defined in Clause
 252.227-7013 (b) (3) of DFARs.  Notwithstanding the foregoing, the
 authors grant the U.S. Government and others acting in its behalf
 permission to use and distribute the software in accordance with the
 terms specified in this license.
 Copyright (c) 1993-1999 Ioi Kim Lam.
 Copyright (c) 2000-2001 Tix Project Group.
 Copyright (c) 2004 ActiveState
 This software is copyrighted by the above entities
 and other parties.  The following terms apply to all files associated
 with the software unless explicitly disclaimed in individual files.
 The authors hereby grant permission to use, copy, modify, distribute,
 and license this software and its documentation for any purpose, provided
 that existing copyright notices are retained in all copies and that this
 notice is included verbatim in any distributions. No written agreement,
 license, or royalty fee is required for any of the authorized uses.
 Modifications to this software may be copyrighted by their authors
 and need not follow the licensing terms described here, provided that
 the new terms are clearly indicated on the first page of each file where
 they apply.
 IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY
 FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 ARISING OUT OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION, OR ANY
 DERIVATIVES THEREOF, EVEN IF THE AUTHORS HAVE BEEN ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
 THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES,
 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT.  THIS SOFTWARE
 IS PROVIDED ON AN "AS IS" BASIS, AND THE AUTHORS AND DISTRIBUTORS HAVE
 NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR
 MODIFICATIONS.
 GOVERNMENT USE: If you are acquiring this software on behalf of the
 U.S. government, the Government shall have only "Restricted Rights"
 in the software and related documentation as defined in the Federal 
 Acquisition Regulations (FARs) in Clause 52.227.19 (c) (2).  If you
 are acquiring the software on behalf of the Department of Defense, the
 software shall be classified as "Commercial Computer Software" and the
 Government shall have only "Restricted Rights" as defined in Clause
 252.227-7013 (c) (1) of DFARs.  Notwithstanding the foregoing, the
 authors grant the U.S. Government and others acting in its behalf
 permission to use and distribute the software in accordance with the
 terms specified in this license. 
 ----------------------------------------------------------------------
 Parts of this software are based on the Tcl/Tk software copyrighted by
 the Regents of the University of California, Sun Microsystems, Inc.,
 and other parties. The original license terms of the Tcl/Tk software
 distribution is included in the file docs/license.tcltk.
 Parts of this software are based on the HTML Library software
 copyrighted by Sun Microsystems, Inc. The original license terms of
 the HTML Library software distribution is included in the file
 docs/license.html_lib.
--- a/Lib/future.py
+++ b/Lib/future.py
@ -0,0 +1,146 @@
 """Record of phased-in incompatible language changes.
 Each line is of the form:
    FeatureName = "_Feature(" OptionalRelease "," MandatoryRelease ","
                              CompilerFlag ")"
 where, normally, OptionalRelease < MandatoryRelease, and both are 5-tuples
 of the same form as sys.version_info:
    (PY_MAJOR_VERSION, # the 2 in 2.1.0a3; an int
     PY_MINOR_VERSION, # the 1; an int
     PY_MICRO_VERSION, # the 0; an int
     PY_RELEASE_LEVEL, # "alpha", "beta", "candidate" or "final"; string
     PY_RELEASE_SERIAL # the 3; an int
    )
 OptionalRelease records the first release in which
    from __future__ import FeatureName
 was accepted.
 In the case of MandatoryReleases that have not yet occurred,
 MandatoryRelease predicts the release in which the feature will become part
 of the language.
 Else MandatoryRelease records when the feature became part of the language;
 in releases at or after that, modules no longer need
    from __future__ import FeatureName
 to use the feature in question, but may continue to use such imports.
 MandatoryRelease may also be None, meaning that a planned feature got
 dropped.
 Instances of class _Feature have two corresponding methods,
 .getOptionalRelease() and .getMandatoryRelease().
 CompilerFlag is the (bitfield) flag that should be passed in the fourth
 argument to the builtin function compile() to enable the feature in
 dynamically compiled code.  This flag is stored in the .compiler_flag
 attribute on _Future instances.  These values must match the appropriate
 #defines of CO_xxx flags in Include/compile.h.
 No feature line is ever to be deleted from this file.
 """
 all_feature_names = [
    "nested_scopes",
    "generators",
    "division",
    "absolute_import",
    "with_statement",
    "print_function",
    "unicode_literals",
    "barry_as_FLUFL",
    "generator_stop",
    "annotations",
 ]
 __all__ = ["all_feature_names"] + all_feature_names
 # The CO_xxx symbols are defined here under the same names defined in
 # code.h and used by compile.h, so that an editor search will find them here.
 # However, they're not exported in __all__, because they don't really belong to
 # this module.
 CO_NESTED            = 0x0010   # nested_scopes
 CO_GENERATOR_ALLOWED = 0        # generators (obsolete, was 0x1000)
 CO_FUTURE_DIVISION   = 0x2000   # division
 CO_FUTURE_ABSOLUTE_IMPORT = 0x4000 # perform absolute imports by default
 CO_FUTURE_WITH_STATEMENT  = 0x8000   # with statement
 CO_FUTURE_PRINT_FUNCTION  = 0x10000   # print function
 CO_FUTURE_UNICODE_LITERALS = 0x20000 # unicode string literals
 CO_FUTURE_BARRY_AS_BDFL = 0x40000
 CO_FUTURE_GENERATOR_STOP  = 0x80000 # StopIteration becomes RuntimeError in generators
 CO_FUTURE_ANNOTATIONS     = 0x100000  # annotations become strings at runtime
 class _Feature:
    def __init__(self, optionalRelease, mandatoryRelease, compiler_flag):
        self.optional = optionalRelease
        self.mandatory = mandatoryRelease
        self.compiler_flag = compiler_flag
    def getOptionalRelease(self):
        """Return first release in which this feature was recognized.
        This is a 5-tuple, of the same form as sys.version_info.
        """
        return self.optional
    def getMandatoryRelease(self):
        """Return release in which this feature will become mandatory.
        This is a 5-tuple, of the same form as sys.version_info, or, if
        the feature was dropped, is None.
        """
        return self.mandatory
    def __repr__(self):
        return "_Feature" + repr((self.optional,
                                  self.mandatory,
                                  self.compiler_flag))
 nested_scopes = _Feature((2, 1, 0, "beta",  1),
                         (2, 2, 0, "alpha", 0),
                         CO_NESTED)
 generators = _Feature((2, 2, 0, "alpha", 1),
                      (2, 3, 0, "final", 0),
                      CO_GENERATOR_ALLOWED)
 division = _Feature((2, 2, 0, "alpha", 2),
                    (3, 0, 0, "alpha", 0),
                    CO_FUTURE_DIVISION)
 absolute_import = _Feature((2, 5, 0, "alpha", 1),
                           (3, 0, 0, "alpha", 0),
                           CO_FUTURE_ABSOLUTE_IMPORT)
 with_statement = _Feature((2, 5, 0, "alpha", 1),
                          (2, 6, 0, "alpha", 0),
                          CO_FUTURE_WITH_STATEMENT)
 print_function = _Feature((2, 6, 0, "alpha", 2),
                          (3, 0, 0, "alpha", 0),
                          CO_FUTURE_PRINT_FUNCTION)
 unicode_literals = _Feature((2, 6, 0, "alpha", 2),
                            (3, 0, 0, "alpha", 0),
                            CO_FUTURE_UNICODE_LITERALS)
 barry_as_FLUFL = _Feature((3, 1, 0, "alpha", 2),
                          (3, 9, 0, "alpha", 0),
                          CO_FUTURE_BARRY_AS_BDFL)
 generator_stop = _Feature((3, 5, 0, "beta", 1),
                          (3, 7, 0, "alpha", 0),
                          CO_FUTURE_GENERATOR_STOP)
 annotations = _Feature((3, 7, 0, "beta", 1),
                       (4, 0, 0, "alpha", 0),
                       CO_FUTURE_ANNOTATIONS)
--- a/Lib/phello.foo.py
+++ b/Lib/phello.foo.py
@ -0,0 +1 @@
 # This file exists as a helper for the test.test_frozen module.
--- a/Lib/_bootlocale.py
+++ b/Lib/_bootlocale.py
@ -0,0 +1,46 @@
 """A minimal subset of the locale module used at interpreter startup
 (imported by the _io module), in order to reduce startup time.
 Don't import directly from third-party code; use the `locale` module instead!
 """
 import sys
 import _locale
 if sys.platform.startswith("win"):
    def getpreferredencoding(do_setlocale=True):
        if sys.flags.utf8_mode:
            return 'UTF-8'
        return _locale._getdefaultlocale()[1]
 else:
    try:
        _locale.CODESET
    except AttributeError:
        if hasattr(sys, 'getandroidapilevel'):
            # On Android langinfo.h and CODESET are missing, and UTF-8 is
            # always used in mbstowcs() and wcstombs().
            def getpreferredencoding(do_setlocale=True):
                return 'UTF-8'
        else:
            def getpreferredencoding(do_setlocale=True):
                if sys.flags.utf8_mode:
                    return 'UTF-8'
                # This path for legacy systems needs the more complex
                # getdefaultlocale() function, import the full locale module.
                import locale
                return locale.getpreferredencoding(do_setlocale)
    else:
        def getpreferredencoding(do_setlocale=True):
            assert not do_setlocale
            if sys.flags.utf8_mode:
                return 'UTF-8'
            result = _locale.nl_langinfo(_locale.CODESET)
            if not result and sys.platform == 'darwin':
                # nl_langinfo can return an empty string
                # when the setting has an invalid value.
                # Default to UTF-8 in that case because
                # UTF-8 is the default charset on OSX and
                # returning nothing will crash the
                # interpreter.
                result = 'UTF-8'
            return result
--- a/Lib/_collections_abc.py
+++ b/Lib/_collections_abc.py
--- a/Lib/_compat_pickle.py
+++ b/Lib/_compat_pickle.py
@ -0,0 +1,251 @@
 # This module is used to map the old Python 2 names to the new names used in
 # Python 3 for the pickle module.  This needed to make pickle streams
 # generated with Python 2 loadable by Python 3.
 # This is a copy of lib2to3.fixes.fix_imports.MAPPING.  We cannot import
 # lib2to3 and use the mapping defined there, because lib2to3 uses pickle.
 # Thus, this could cause the module to be imported recursively.
 IMPORT_MAPPING = {
    '__builtin__' : 'builtins',
    'copy_reg': 'copyreg',
    'Queue': 'queue',
    'SocketServer': 'socketserver',
    'ConfigParser': 'configparser',
    'repr': 'reprlib',
    'tkFileDialog': 'tkinter.filedialog',
    'tkSimpleDialog': 'tkinter.simpledialog',
    'tkColorChooser': 'tkinter.colorchooser',
    'tkCommonDialog': 'tkinter.commondialog',
    'Dialog': 'tkinter.dialog',
    'Tkdnd': 'tkinter.dnd',
    'tkFont': 'tkinter.font',
    'tkMessageBox': 'tkinter.messagebox',
    'ScrolledText': 'tkinter.scrolledtext',
    'Tkconstants': 'tkinter.constants',
    'Tix': 'tkinter.tix',
    'ttk': 'tkinter.ttk',
    'Tkinter': 'tkinter',
    'markupbase': '_markupbase',
    '_winreg': 'winreg',
    'thread': '_thread',
    'dummy_thread': '_dummy_thread',
    'dbhash': 'dbm.bsd',
    'dumbdbm': 'dbm.dumb',
    'dbm': 'dbm.ndbm',
    'gdbm': 'dbm.gnu',
    'xmlrpclib': 'xmlrpc.client',
    'SimpleXMLRPCServer': 'xmlrpc.server',
    'httplib': 'http.client',
    'htmlentitydefs' : 'html.entities',
    'HTMLParser' : 'html.parser',
    'Cookie': 'http.cookies',
    'cookielib': 'http.cookiejar',
    'BaseHTTPServer': 'http.server',
    'test.test_support': 'test.support',
    'commands': 'subprocess',
    'urlparse' : 'urllib.parse',
    'robotparser' : 'urllib.robotparser',
    'urllib2': 'urllib.request',
    'anydbm': 'dbm',
    '_abcoll' : 'collections.abc',
 }
 # This contains rename rules that are easy to handle.  We ignore the more
 # complex stuff (e.g. mapping the names in the urllib and types modules).
 # These rules should be run before import names are fixed.
 NAME_MAPPING = {
    ('__builtin__', 'xrange'):     ('builtins', 'range'),
    ('__builtin__', 'reduce'):     ('functools', 'reduce'),
    ('__builtin__', 'intern'):     ('sys', 'intern'),
    ('__builtin__', 'unichr'):     ('builtins', 'chr'),
    ('__builtin__', 'unicode'):    ('builtins', 'str'),
    ('__builtin__', 'long'):       ('builtins', 'int'),
    ('itertools', 'izip'):         ('builtins', 'zip'),
    ('itertools', 'imap'):         ('builtins', 'map'),
    ('itertools', 'ifilter'):      ('builtins', 'filter'),
    ('itertools', 'ifilterfalse'): ('itertools', 'filterfalse'),
    ('itertools', 'izip_longest'): ('itertools', 'zip_longest'),
    ('UserDict', 'IterableUserDict'): ('collections', 'UserDict'),
    ('UserList', 'UserList'): ('collections', 'UserList'),
    ('UserString', 'UserString'): ('collections', 'UserString'),
    ('whichdb', 'whichdb'): ('dbm', 'whichdb'),
    ('_socket', 'fromfd'): ('socket', 'fromfd'),
    ('_multiprocessing', 'Connection'): ('multiprocessing.connection', 'Connection'),
    ('multiprocessing.process', 'Process'): ('multiprocessing.context', 'Process'),
    ('multiprocessing.forking', 'Popen'): ('multiprocessing.popen_fork', 'Popen'),
    ('urllib', 'ContentTooShortError'): ('urllib.error', 'ContentTooShortError'),
    ('urllib', 'getproxies'): ('urllib.request', 'getproxies'),
    ('urllib', 'pathname2url'): ('urllib.request', 'pathname2url'),
    ('urllib', 'quote_plus'): ('urllib.parse', 'quote_plus'),
    ('urllib', 'quote'): ('urllib.parse', 'quote'),
    ('urllib', 'unquote_plus'): ('urllib.parse', 'unquote_plus'),
    ('urllib', 'unquote'): ('urllib.parse', 'unquote'),
    ('urllib', 'url2pathname'): ('urllib.request', 'url2pathname'),
    ('urllib', 'urlcleanup'): ('urllib.request', 'urlcleanup'),
    ('urllib', 'urlencode'): ('urllib.parse', 'urlencode'),
    ('urllib', 'urlopen'): ('urllib.request', 'urlopen'),
    ('urllib', 'urlretrieve'): ('urllib.request', 'urlretrieve'),
    ('urllib2', 'HTTPError'): ('urllib.error', 'HTTPError'),
    ('urllib2', 'URLError'): ('urllib.error', 'URLError'),
 }
 PYTHON2_EXCEPTIONS = (
    "ArithmeticError",
    "AssertionError",
    "AttributeError",
    "BaseException",
    "BufferError",
    "BytesWarning",
    "DeprecationWarning",
    "EOFError",
    "EnvironmentError",
    "Exception",
    "FloatingPointError",
    "FutureWarning",
    "GeneratorExit",
    "IOError",
    "ImportError",
    "ImportWarning",
    "IndentationError",
    "IndexError",
    "KeyError",
    "KeyboardInterrupt",
    "LookupError",
    "MemoryError",
    "NameError",
    "NotImplementedError",
    "OSError",
    "OverflowError",
    "PendingDeprecationWarning",
    "ReferenceError",
    "RuntimeError",
    "RuntimeWarning",
    # StandardError is gone in Python 3, so we map it to Exception
    "StopIteration",
    "SyntaxError",
    "SyntaxWarning",
    "SystemError",
    "SystemExit",
    "TabError",
    "TypeError",
    "UnboundLocalError",
    "UnicodeDecodeError",
    "UnicodeEncodeError",
    "UnicodeError",
    "UnicodeTranslateError",
    "UnicodeWarning",
    "UserWarning",
    "ValueError",
    "Warning",
    "ZeroDivisionError",
 )
 try:
    WindowsError
 except NameError:
    pass
 else:
    PYTHON2_EXCEPTIONS += ("WindowsError",)
 for excname in PYTHON2_EXCEPTIONS:
    NAME_MAPPING[("exceptions", excname)] = ("builtins", excname)
 MULTIPROCESSING_EXCEPTIONS = (
    'AuthenticationError',
    'BufferTooShort',
    'ProcessError',
    'TimeoutError',
 )
 for excname in MULTIPROCESSING_EXCEPTIONS:
    NAME_MAPPING[("multiprocessing", excname)] = ("multiprocessing.context", excname)
 # Same, but for 3.x to 2.x
 REVERSE_IMPORT_MAPPING = dict((v, k) for (k, v) in IMPORT_MAPPING.items())
 assert len(REVERSE_IMPORT_MAPPING) == len(IMPORT_MAPPING)
 REVERSE_NAME_MAPPING = dict((v, k) for (k, v) in NAME_MAPPING.items())
 assert len(REVERSE_NAME_MAPPING) == len(NAME_MAPPING)
 # Non-mutual mappings.
 IMPORT_MAPPING.update({
    'cPickle': 'pickle',
    '_elementtree': 'xml.etree.ElementTree',
    'FileDialog': 'tkinter.filedialog',
    'SimpleDialog': 'tkinter.simpledialog',
    'DocXMLRPCServer': 'xmlrpc.server',
    'SimpleHTTPServer': 'http.server',
    'CGIHTTPServer': 'http.server',
    # For compatibility with broken pickles saved in old Python 3 versions
    'UserDict': 'collections',
    'UserList': 'collections',
    'UserString': 'collections',
    'whichdb': 'dbm',
    'StringIO':  'io',
    'cStringIO': 'io',
 })
 REVERSE_IMPORT_MAPPING.update({
    '_bz2': 'bz2',
    '_dbm': 'dbm',
    '_functools': 'functools',
    '_gdbm': 'gdbm',
    '_pickle': 'pickle',
 })
 NAME_MAPPING.update({
    ('__builtin__', 'basestring'): ('builtins', 'str'),
    ('exceptions', 'StandardError'): ('builtins', 'Exception'),
    ('UserDict', 'UserDict'): ('collections', 'UserDict'),
    ('socket', '_socketobject'): ('socket', 'SocketType'),
 })
 REVERSE_NAME_MAPPING.update({
    ('_functools', 'reduce'): ('__builtin__', 'reduce'),
    ('tkinter.filedialog', 'FileDialog'): ('FileDialog', 'FileDialog'),
    ('tkinter.filedialog', 'LoadFileDialog'): ('FileDialog', 'LoadFileDialog'),
    ('tkinter.filedialog', 'SaveFileDialog'): ('FileDialog', 'SaveFileDialog'),
    ('tkinter.simpledialog', 'SimpleDialog'): ('SimpleDialog', 'SimpleDialog'),
    ('xmlrpc.server', 'ServerHTMLDoc'): ('DocXMLRPCServer', 'ServerHTMLDoc'),
    ('xmlrpc.server', 'XMLRPCDocGenerator'):
        ('DocXMLRPCServer', 'XMLRPCDocGenerator'),
    ('xmlrpc.server', 'DocXMLRPCRequestHandler'):
        ('DocXMLRPCServer', 'DocXMLRPCRequestHandler'),
    ('xmlrpc.server', 'DocXMLRPCServer'):
        ('DocXMLRPCServer', 'DocXMLRPCServer'),
    ('xmlrpc.server', 'DocCGIXMLRPCRequestHandler'):
        ('DocXMLRPCServer', 'DocCGIXMLRPCRequestHandler'),
    ('http.server', 'SimpleHTTPRequestHandler'):
        ('SimpleHTTPServer', 'SimpleHTTPRequestHandler'),
    ('http.server', 'CGIHTTPRequestHandler'):
        ('CGIHTTPServer', 'CGIHTTPRequestHandler'),
    ('_socket', 'socket'): ('socket', '_socketobject'),
 })
 PYTHON3_OSERROR_EXCEPTIONS = (
    'BrokenPipeError',
    'ChildProcessError',
    'ConnectionAbortedError',
    'ConnectionError',
    'ConnectionRefusedError',
    'ConnectionResetError',
    'FileExistsError',
    'FileNotFoundError',
    'InterruptedError',
    'IsADirectoryError',
    'NotADirectoryError',
    'PermissionError',
    'ProcessLookupError',
    'TimeoutError',
 )
 for excname in PYTHON3_OSERROR_EXCEPTIONS:
    REVERSE_NAME_MAPPING[('builtins', excname)] = ('exceptions', 'OSError')
 PYTHON3_IMPORTERROR_EXCEPTIONS = (
    'ModuleNotFoundError',
 )
 for excname in PYTHON3_IMPORTERROR_EXCEPTIONS:
    REVERSE_NAME_MAPPING[('builtins', excname)] = ('exceptions', 'ImportError')
--- a/Lib/_compression.py
+++ b/Lib/_compression.py
@ -0,0 +1,152 @@
 """Internal classes used by the gzip, lzma and bz2 modules"""
 import io
 BUFFER_SIZE = io.DEFAULT_BUFFER_SIZE  # Compressed data read chunk size
 class BaseStream(io.BufferedIOBase):
    """Mode-checking helper functions."""
    def _check_not_closed(self):
        if self.closed:
            raise ValueError("I/O operation on closed file")
    def _check_can_read(self):
        if not self.readable():
            raise io.UnsupportedOperation("File not open for reading")
    def _check_can_write(self):
        if not self.writable():
            raise io.UnsupportedOperation("File not open for writing")
    def _check_can_seek(self):
        if not self.readable():
            raise io.UnsupportedOperation("Seeking is only supported "
                                          "on files open for reading")
        if not self.seekable():
            raise io.UnsupportedOperation("The underlying file object "
                                          "does not support seeking")
 class DecompressReader(io.RawIOBase):
    """Adapts the decompressor API to a RawIOBase reader API"""
    def readable(self):
        return True
    def __init__(self, fp, decomp_factory, trailing_error=(), **decomp_args):
        self._fp = fp
        self._eof = False
        self._pos = 0  # Current offset in decompressed stream
        # Set to size of decompressed stream once it is known, for SEEK_END
        self._size = -1
        # Save the decompressor factory and arguments.
        # If the file contains multiple compressed streams, each
        # stream will need a separate decompressor object. A new decompressor
        # object is also needed when implementing a backwards seek().
        self._decomp_factory = decomp_factory
        self._decomp_args = decomp_args
        self._decompressor = self._decomp_factory(**self._decomp_args)
        # Exception class to catch from decompressor signifying invalid
        # trailing data to ignore
        self._trailing_error = trailing_error
    def close(self):
        self._decompressor = None
        return super().close()
    def seekable(self):
        return self._fp.seekable()
    def readinto(self, b):
        with memoryview(b) as view, view.cast("B") as byte_view:
            data = self.read(len(byte_view))
            byte_view[:len(data)] = data
        return len(data)
    def read(self, size=-1):
        if size < 0:
            return self.readall()
        if not size or self._eof:
            return b""
        data = None  # Default if EOF is encountered
        # Depending on the input data, our call to the decompressor may not
        # return any data. In this case, try again after reading another block.
        while True:
            if self._decompressor.eof:
                rawblock = (self._decompressor.unused_data or
                            self._fp.read(BUFFER_SIZE))
                if not rawblock:
                    break
                # Continue to next stream.
                self._decompressor = self._decomp_factory(
                    **self._decomp_args)
                try:
                    data = self._decompressor.decompress(rawblock, size)
                except self._trailing_error:
                    # Trailing data isn't a valid compressed stream; ignore it.
                    break
            else:
                if self._decompressor.needs_input:
                    rawblock = self._fp.read(BUFFER_SIZE)
                    if not rawblock:
                        raise EOFError("Compressed file ended before the "
                                       "end-of-stream marker was reached")
                else:
                    rawblock = b""
                data = self._decompressor.decompress(rawblock, size)
            if data:
                break
        if not data:
            self._eof = True
            self._size = self._pos
            return b""
        self._pos += len(data)
        return data
    # Rewind the file to the beginning of the data stream.
    def _rewind(self):
        self._fp.seek(0)
        self._eof = False
        self._pos = 0
        self._decompressor = self._decomp_factory(**self._decomp_args)
    def seek(self, offset, whence=io.SEEK_SET):
        # Recalculate offset as an absolute file position.
        if whence == io.SEEK_SET:
            pass
        elif whence == io.SEEK_CUR:
            offset = self._pos + offset
        elif whence == io.SEEK_END:
            # Seeking relative to EOF - we need to know the file's size.
            if self._size < 0:
                while self.read(io.DEFAULT_BUFFER_SIZE):
                    pass
            offset = self._size + offset
        else:
            raise ValueError("Invalid value for whence: {}".format(whence))
        # Make it so that offset is the number of bytes to skip forward.
        if offset < self._pos:
            self._rewind()
        else:
            offset -= self._pos
        # Read and discard data until we reach the desired position.
        while offset > 0:
            data = self.read(min(io.DEFAULT_BUFFER_SIZE, offset))
            if not data:
                break
            offset -= len(data)
        return self._pos
    def tell(self):
        """Return the current file position."""
        return self._pos
--- a/Lib/_dummy_thread.py
+++ b/Lib/_dummy_thread.py
@ -0,0 +1,163 @@
 """Drop-in replacement for the thread module.
 Meant to be used as a brain-dead substitute so that threaded code does
 not need to be rewritten for when the thread module is not present.
 Suggested usage is::
    try:
        import _thread
    except ImportError:
        import _dummy_thread as _thread
 """
 # Exports only things specified by thread documentation;
 # skipping obsolete synonyms allocate(), start_new(), exit_thread().
 __all__ = ['error', 'start_new_thread', 'exit', 'get_ident', 'allocate_lock',
           'interrupt_main', 'LockType']
 # A dummy value
 TIMEOUT_MAX = 2**31
 # NOTE: this module can be imported early in the extension building process,
 # and so top level imports of other modules should be avoided.  Instead, all
 # imports are done when needed on a function-by-function basis.  Since threads
 # are disabled, the import lock should not be an issue anyway (??).
 error = RuntimeError
 def start_new_thread(function, args, kwargs={}):
    """Dummy implementation of _thread.start_new_thread().
    Compatibility is maintained by making sure that ``args`` is a
    tuple and ``kwargs`` is a dictionary.  If an exception is raised
    and it is SystemExit (which can be done by _thread.exit()) it is
    caught and nothing is done; all other exceptions are printed out
    by using traceback.print_exc().
    If the executed function calls interrupt_main the KeyboardInterrupt will be
    raised when the function returns.
    """
    if type(args) != type(tuple()):
        raise TypeError("2nd arg must be a tuple")
    if type(kwargs) != type(dict()):
        raise TypeError("3rd arg must be a dict")
    global _main
    _main = False
    try:
        function(*args, **kwargs)
    except SystemExit:
        pass
    except:
        import traceback
        traceback.print_exc()
    _main = True
    global _interrupt
    if _interrupt:
        _interrupt = False
        raise KeyboardInterrupt
 def exit():
    """Dummy implementation of _thread.exit()."""
    raise SystemExit
 def get_ident():
    """Dummy implementation of _thread.get_ident().
    Since this module should only be used when _threadmodule is not
    available, it is safe to assume that the current process is the
    only thread.  Thus a constant can be safely returned.
    """
    return 1
 def allocate_lock():
    """Dummy implementation of _thread.allocate_lock()."""
    return LockType()
 def stack_size(size=None):
    """Dummy implementation of _thread.stack_size()."""
    if size is not None:
        raise error("setting thread stack size not supported")
    return 0
 def _set_sentinel():
    """Dummy implementation of _thread._set_sentinel()."""
    return LockType()
 class LockType(object):
    """Class implementing dummy implementation of _thread.LockType.
    Compatibility is maintained by maintaining self.locked_status
    which is a boolean that stores the state of the lock.  Pickling of
    the lock, though, should not be done since if the _thread module is
    then used with an unpickled ``lock()`` from here problems could
    occur from this class not having atomic methods.
    """
    def __init__(self):
        self.locked_status = False
    def acquire(self, waitflag=None, timeout=-1):
        """Dummy implementation of acquire().
        For blocking calls, self.locked_status is automatically set to
        True and returned appropriately based on value of
        ``waitflag``.  If it is non-blocking, then the value is
        actually checked and not set if it is already acquired.  This
        is all done so that threading.Condition's assert statements
        aren't triggered and throw a little fit.
        """
        if waitflag is None or waitflag:
            self.locked_status = True
            return True
        else:
            if not self.locked_status:
                self.locked_status = True
                return True
            else:
                if timeout > 0:
                    import time
                    time.sleep(timeout)
                return False
    __enter__ = acquire
    def __exit__(self, typ, val, tb):
        self.release()
    def release(self):
        """Release the dummy lock."""
        # XXX Perhaps shouldn't actually bother to test?  Could lead
        #     to problems for complex, threaded code.
        if not self.locked_status:
            raise error
        self.locked_status = False
        return True
    def locked(self):
        return self.locked_status
    def __repr__(self):
        return "<%s %s.%s object at %s>" % (
            "locked" if self.locked_status else "unlocked",
            self.__class__.__module__,
            self.__class__.__qualname__,
            hex(id(self))
        )
 # Used to signal that interrupt_main was called in a "thread"
 _interrupt = False
 # True when not executing in a "thread"
 _main = True
 def interrupt_main():
    """Set _interrupt flag to True to have start_new_thread raise
    KeyboardInterrupt upon exiting."""
    if _main:
        raise KeyboardInterrupt
    else:
        global _interrupt
        _interrupt = True
--- a/Lib/_markupbase.py
+++ b/Lib/_markupbase.py
@ -0,0 +1,395 @@
 """Shared support for scanning document type declarations in HTML and XHTML.
 This module is used as a foundation for the html.parser module.  It has no
 documented public API and should not be used directly.
 """
 import re
 _declname_match = re.compile(r'[a-zA-Z][-_.a-zA-Z0-9]*\s*').match
 _declstringlit_match = re.compile(r'(\'[^\']*\'|"[^"]*")\s*').match
 _commentclose = re.compile(r'--\s*>')
 _markedsectionclose = re.compile(r']\s*]\s*>')
 # An analysis of the MS-Word extensions is available at
 # http://www.planetpublish.com/xmlarena/xap/Thursday/WordtoXML.pdf
 _msmarkedsectionclose = re.compile(r']\s*>')
 del re
 class ParserBase:
    """Parser base class which provides some common support methods used
    by the SGML/HTML and XHTML parsers."""
    def __init__(self):
        if self.__class__ is ParserBase:
            raise RuntimeError(
                "_markupbase.ParserBase must be subclassed")
    def error(self, message):
        raise NotImplementedError(
            "subclasses of ParserBase must override error()")
    def reset(self):
        self.lineno = 1
        self.offset = 0
    def getpos(self):
        """Return current line number and offset."""
        return self.lineno, self.offset
    # Internal -- update line number and offset.  This should be
    # called for each piece of data exactly once, in order -- in other
    # words the concatenation of all the input strings to this
    # function should be exactly the entire input.
    def updatepos(self, i, j):
        if i >= j:
            return j
        rawdata = self.rawdata
        nlines = rawdata.count("\n", i, j)
        if nlines:
            self.lineno = self.lineno + nlines
            pos = rawdata.rindex("\n", i, j) # Should not fail
            self.offset = j-(pos+1)
        else:
            self.offset = self.offset + j-i
        return j
    _decl_otherchars = ''
    # Internal -- parse declaration (for use by subclasses).
    def parse_declaration(self, i):
        # This is some sort of declaration; in "HTML as
        # deployed," this should only be the document type
        # declaration ("<!DOCTYPE html...>").
        # ISO 8879:1986, however, has more complex
        # declaration syntax for elements in <!...>, including:
        # --comment--
        # [marked section]
        # name in the following list: ENTITY, DOCTYPE, ELEMENT,
        # ATTLIST, NOTATION, SHORTREF, USEMAP,
        # LINKTYPE, LINK, IDLINK, USELINK, SYSTEM
        rawdata = self.rawdata
        j = i + 2
        assert rawdata[i:j] == "<!", "unexpected call to parse_declaration"
        if rawdata[j:j+1] == ">":
            # the empty comment <!>
            return j + 1
        if rawdata[j:j+1] in ("-", ""):
            # Start of comment followed by buffer boundary,
            # or just a buffer boundary.
            return -1
        # A simple, practical version could look like: ((name|stringlit) S*) + '>'
        n = len(rawdata)
        if rawdata[j:j+2] == '--': #comment
            # Locate --.*-- as the body of the comment
            return self.parse_comment(i)
        elif rawdata[j] == '[': #marked section
            # Locate [statusWord [...arbitrary SGML...]] as the body of the marked section
            # Where statusWord is one of TEMP, CDATA, IGNORE, INCLUDE, RCDATA
            # Note that this is extended by Microsoft Office "Save as Web" function
            # to include [if...] and [endif].
            return self.parse_marked_section(i)
        else: #all other declaration elements
            decltype, j = self._scan_name(j, i)
        if j < 0:
            return j
        if decltype == "doctype":
            self._decl_otherchars = ''
        while j < n:
            c = rawdata[j]
            if c == ">":
                # end of declaration syntax
                data = rawdata[i+2:j]
                if decltype == "doctype":
                    self.handle_decl(data)
                else:
                    # According to the HTML5 specs sections "8.2.4.44 Bogus
                    # comment state" and "8.2.4.45 Markup declaration open
                    # state", a comment token should be emitted.
                    # Calling unknown_decl provides more flexibility though.
                    self.unknown_decl(data)
                return j + 1
            if c in "\"'":
                m = _declstringlit_match(rawdata, j)
                if not m:
                    return -1 # incomplete
                j = m.end()
            elif c in "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ":
                name, j = self._scan_name(j, i)
            elif c in self._decl_otherchars:
                j = j + 1
            elif c == "[":
                # this could be handled in a separate doctype parser
                if decltype == "doctype":
                    j = self._parse_doctype_subset(j + 1, i)
                elif decltype in {"attlist", "linktype", "link", "element"}:
                    # must tolerate []'d groups in a content model in an element declaration
                    # also in data attribute specifications of attlist declaration
                    # also link type declaration subsets in linktype declarations
                    # also link attribute specification lists in link declarations
                    self.error("unsupported '[' char in %s declaration" % decltype)
                else:
                    self.error("unexpected '[' char in declaration")
            else:
                self.error(
                    "unexpected %r char in declaration" % rawdata[j])
            if j < 0:
                return j
        return -1 # incomplete
    # Internal -- parse a marked section
    # Override this to handle MS-word extension syntax <![if word]>content<![endif]>
    def parse_marked_section(self, i, report=1):
        rawdata= self.rawdata
        assert rawdata[i:i+3] == '<![', "unexpected call to parse_marked_section()"
        sectName, j = self._scan_name( i+3, i )
        if j < 0:
            return j
        if sectName in {"temp", "cdata", "ignore", "include", "rcdata"}:
            # look for standard ]]> ending
            match= _markedsectionclose.search(rawdata, i+3)
        elif sectName in {"if", "else", "endif"}:
            # look for MS Office ]> ending
            match= _msmarkedsectionclose.search(rawdata, i+3)
        else:
            self.error('unknown status keyword %r in marked section' % rawdata[i+3:j])
        if not match:
            return -1
        if report:
            j = match.start(0)
            self.unknown_decl(rawdata[i+3: j])
        return match.end(0)
    # Internal -- parse comment, return length or -1 if not terminated
    def parse_comment(self, i, report=1):
        rawdata = self.rawdata
        if rawdata[i:i+4] != '<!--':
            self.error('unexpected call to parse_comment()')
        match = _commentclose.search(rawdata, i+4)
        if not match:
            return -1
        if report:
            j = match.start(0)
            self.handle_comment(rawdata[i+4: j])
        return match.end(0)
    # Internal -- scan past the internal subset in a <!DOCTYPE declaration,
    # returning the index just past any whitespace following the trailing ']'.
    def _parse_doctype_subset(self, i, declstartpos):
        rawdata = self.rawdata
        n = len(rawdata)
        j = i
        while j < n:
            c = rawdata[j]
            if c == "<":
                s = rawdata[j:j+2]
                if s == "<":
                    # end of buffer; incomplete
                    return -1
                if s != "<!":
                    self.updatepos(declstartpos, j + 1)
                    self.error("unexpected char in internal subset (in %r)" % s)
                if (j + 2) == n:
                    # end of buffer; incomplete
                    return -1
                if (j + 4) > n:
                    # end of buffer; incomplete
                    return -1
                if rawdata[j:j+4] == "<!--":
                    j = self.parse_comment(j, report=0)
                    if j < 0:
                        return j
                    continue
                name, j = self._scan_name(j + 2, declstartpos)
                if j == -1:
                    return -1
                if name not in {"attlist", "element", "entity", "notation"}:
                    self.updatepos(declstartpos, j + 2)
                    self.error(
                        "unknown declaration %r in internal subset" % name)
                # handle the individual names
                meth = getattr(self, "_parse_doctype_" + name)
                j = meth(j, declstartpos)
                if j < 0:
                    return j
            elif c == "%":
                # parameter entity reference
                if (j + 1) == n:
                    # end of buffer; incomplete
                    return -1
                s, j = self._scan_name(j + 1, declstartpos)
                if j < 0:
                    return j
                if rawdata[j] == ";":
                    j = j + 1
            elif c == "]":
                j = j + 1
                while j < n and rawdata[j].isspace():
                    j = j + 1
                if j < n:
                    if rawdata[j] == ">":
                        return j
                    self.updatepos(declstartpos, j)
                    self.error("unexpected char after internal subset")
                else:
                    return -1
            elif c.isspace():
                j = j + 1
            else:
                self.updatepos(declstartpos, j)
                self.error("unexpected char %r in internal subset" % c)
        # end of buffer reached
        return -1
    # Internal -- scan past <!ELEMENT declarations
    def _parse_doctype_element(self, i, declstartpos):
        name, j = self._scan_name(i, declstartpos)
        if j == -1:
            return -1
        # style content model; just skip until '>'
        rawdata = self.rawdata
        if '>' in rawdata[j:]:
            return rawdata.find(">", j) + 1
        return -1
    # Internal -- scan past <!ATTLIST declarations
    def _parse_doctype_attlist(self, i, declstartpos):
        rawdata = self.rawdata
        name, j = self._scan_name(i, declstartpos)
        c = rawdata[j:j+1]
        if c == "":
            return -1
        if c == ">":
            return j + 1
        while 1:
            # scan a series of attribute descriptions; simplified:
            #   name type [value] [#constraint]
            name, j = self._scan_name(j, declstartpos)
            if j < 0:
                return j
            c = rawdata[j:j+1]
            if c == "":
                return -1
            if c == "(":
                # an enumerated type; look for ')'
                if ")" in rawdata[j:]:
                    j = rawdata.find(")", j) + 1
                else:
                    return -1
                while rawdata[j:j+1].isspace():
                    j = j + 1
                if not rawdata[j:]:
                    # end of buffer, incomplete
                    return -1
            else:
                name, j = self._scan_name(j, declstartpos)
            c = rawdata[j:j+1]
            if not c:
                return -1
            if c in "'\"":
                m = _declstringlit_match(rawdata, j)
                if m:
                    j = m.end()
                else:
                    return -1
                c = rawdata[j:j+1]
                if not c:
                    return -1
            if c == "#":
                if rawdata[j:] == "#":
                    # end of buffer
                    return -1
                name, j = self._scan_name(j + 1, declstartpos)
                if j < 0:
                    return j
                c = rawdata[j:j+1]
                if not c:
                    return -1
            if c == '>':
                # all done
                return j + 1
    # Internal -- scan past <!NOTATION declarations
    def _parse_doctype_notation(self, i, declstartpos):
        name, j = self._scan_name(i, declstartpos)
        if j < 0:
            return j
        rawdata = self.rawdata
        while 1:
            c = rawdata[j:j+1]
            if not c:
                # end of buffer; incomplete
                return -1
            if c == '>':
                return j + 1
            if c in "'\"":
                m = _declstringlit_match(rawdata, j)
                if not m:
                    return -1
                j = m.end()
            else:
                name, j = self._scan_name(j, declstartpos)
                if j < 0:
                    return j
    # Internal -- scan past <!ENTITY declarations
    def _parse_doctype_entity(self, i, declstartpos):
        rawdata = self.rawdata
        if rawdata[i:i+1] == "%":
            j = i + 1
            while 1:
                c = rawdata[j:j+1]
                if not c:
                    return -1
                if c.isspace():
                    j = j + 1
                else:
                    break
        else:
            j = i
        name, j = self._scan_name(j, declstartpos)
        if j < 0:
            return j
        while 1:
            c = self.rawdata[j:j+1]
            if not c:
                return -1
            if c in "'\"":
                m = _declstringlit_match(rawdata, j)
                if m:
                    j = m.end()
                else:
                    return -1    # incomplete
            elif c == ">":
                return j + 1
            else:
                name, j = self._scan_name(j, declstartpos)
                if j < 0:
                    return j
    # Internal -- scan a name token and the new position and the token, or
    # return -1 if we've reached the end of the buffer.
    def _scan_name(self, i, declstartpos):
        rawdata = self.rawdata
        n = len(rawdata)
        if i == n:
            return None, -1
        m = _declname_match(rawdata, i)
        if m:
            s = m.group()
            name = s.strip()
            if (i + len(s)) == n:
                return None, -1  # end of buffer
            return name.lower(), m.end()
        else:
            self.updatepos(declstartpos, i)
            self.error("expected name token at %r"
                       % rawdata[declstartpos:declstartpos+20])
    # To be overridden -- handlers for unknown objects
    def unknown_decl(self, data):
        pass
--- a/Lib/_osx_support.py
+++ b/Lib/_osx_support.py
@ -0,0 +1,502 @@
 """Shared OS X support functions."""
 import os
 import re
 import sys
 __all__ = [
    'compiler_fixup',
    'customize_config_vars',
    'customize_compiler',
    'get_platform_osx',
 ]
 # configuration variables that may contain universal build flags,
 # like "-arch" or "-isdkroot", that may need customization for
 # the user environment
 _UNIVERSAL_CONFIG_VARS = ('CFLAGS', 'LDFLAGS', 'CPPFLAGS', 'BASECFLAGS',
                            'BLDSHARED', 'LDSHARED', 'CC', 'CXX',
                            'PY_CFLAGS', 'PY_LDFLAGS', 'PY_CPPFLAGS',
                            'PY_CORE_CFLAGS', 'PY_CORE_LDFLAGS')
 # configuration variables that may contain compiler calls
 _COMPILER_CONFIG_VARS = ('BLDSHARED', 'LDSHARED', 'CC', 'CXX')
 # prefix added to original configuration variable names
 _INITPRE = '_OSX_SUPPORT_INITIAL_'
 def _find_executable(executable, path=None):
    """Tries to find 'executable' in the directories listed in 'path'.
    A string listing directories separated by 'os.pathsep'; defaults to
    os.environ['PATH'].  Returns the complete filename or None if not found.
    """
    if path is None:
        path = os.environ['PATH']
    paths = path.split(os.pathsep)
    base, ext = os.path.splitext(executable)
    if (sys.platform == 'win32') and (ext != '.exe'):
        executable = executable + '.exe'
    if not os.path.isfile(executable):
        for p in paths:
            f = os.path.join(p, executable)
            if os.path.isfile(f):
                # the file exists, we have a shot at spawn working
                return f
        return None
    else:
        return executable
 def _read_output(commandstring):
    """Output from successful command execution or None"""
    # Similar to os.popen(commandstring, "r").read(),
    # but without actually using os.popen because that
    # function is not usable during python bootstrap.
    # tempfile is also not available then.
    import contextlib
    try:
        import tempfile
        fp = tempfile.NamedTemporaryFile()
    except ImportError:
        fp = open("/tmp/_osx_support.%s"%(
            os.getpid(),), "w+b")
    with contextlib.closing(fp) as fp:
        cmd = "%s 2>/dev/null >'%s'" % (commandstring, fp.name)
        return fp.read().decode('utf-8').strip() if not os.system(cmd) else None
 def _find_build_tool(toolname):
    """Find a build tool on current path or using xcrun"""
    return (_find_executable(toolname)
                or _read_output("/usr/bin/xcrun -find %s" % (toolname,))
                or ''
            )
 _SYSTEM_VERSION = None
 def _get_system_version():
    """Return the OS X system version as a string"""
    # Reading this plist is a documented way to get the system
    # version (see the documentation for the Gestalt Manager)
    # We avoid using platform.mac_ver to avoid possible bootstrap issues during
    # the build of Python itself (distutils is used to build standard library
    # extensions).
    global _SYSTEM_VERSION
    if _SYSTEM_VERSION is None:
        _SYSTEM_VERSION = ''
        try:
            f = open('/System/Library/CoreServices/SystemVersion.plist')
        except OSError:
            # We're on a plain darwin box, fall back to the default
            # behaviour.
            pass
        else:
            try:
                m = re.search(r'<key>ProductUserVisibleVersion</key>\s*'
                              r'<string>(.*?)</string>', f.read())
            finally:
                f.close()
            if m is not None:
                _SYSTEM_VERSION = '.'.join(m.group(1).split('.')[:2])
            # else: fall back to the default behaviour
    return _SYSTEM_VERSION
 def _remove_original_values(_config_vars):
    """Remove original unmodified values for testing"""
    # This is needed for higher-level cross-platform tests of get_platform.
    for k in list(_config_vars):
        if k.startswith(_INITPRE):
            del _config_vars[k]
 def _save_modified_value(_config_vars, cv, newvalue):
    """Save modified and original unmodified value of configuration var"""
    oldvalue = _config_vars.get(cv, '')
    if (oldvalue != newvalue) and (_INITPRE + cv not in _config_vars):
        _config_vars[_INITPRE + cv] = oldvalue
    _config_vars[cv] = newvalue
 def _supports_universal_builds():
    """Returns True if universal builds are supported on this system"""
    # As an approximation, we assume that if we are running on 10.4 or above,
    # then we are running with an Xcode environment that supports universal
    # builds, in particular -isysroot and -arch arguments to the compiler. This
    # is in support of allowing 10.4 universal builds to run on 10.3.x systems.
    osx_version = _get_system_version()
    if osx_version:
        try:
            osx_version = tuple(int(i) for i in osx_version.split('.'))
        except ValueError:
            osx_version = ''
    return bool(osx_version >= (10, 4)) if osx_version else False
 def _find_appropriate_compiler(_config_vars):
    """Find appropriate C compiler for extension module builds"""
    # Issue #13590:
    #    The OSX location for the compiler varies between OSX
    #    (or rather Xcode) releases.  With older releases (up-to 10.5)
    #    the compiler is in /usr/bin, with newer releases the compiler
    #    can only be found inside Xcode.app if the "Command Line Tools"
    #    are not installed.
    #
    #    Furthermore, the compiler that can be used varies between
    #    Xcode releases. Up to Xcode 4 it was possible to use 'gcc-4.2'
    #    as the compiler, after that 'clang' should be used because
    #    gcc-4.2 is either not present, or a copy of 'llvm-gcc' that
    #    miscompiles Python.
    # skip checks if the compiler was overridden with a CC env variable
    if 'CC' in os.environ:
        return _config_vars
    # The CC config var might contain additional arguments.
    # Ignore them while searching.
    cc = oldcc = _config_vars['CC'].split()[0]
    if not _find_executable(cc):
        # Compiler is not found on the shell search PATH.
        # Now search for clang, first on PATH (if the Command LIne
        # Tools have been installed in / or if the user has provided
        # another location via CC).  If not found, try using xcrun
        # to find an uninstalled clang (within a selected Xcode).
        # NOTE: Cannot use subprocess here because of bootstrap
        # issues when building Python itself (and os.popen is
        # implemented on top of subprocess and is therefore not
        # usable as well)
        cc = _find_build_tool('clang')
    elif os.path.basename(cc).startswith('gcc'):
        # Compiler is GCC, check if it is LLVM-GCC
        data = _read_output("'%s' --version"
                             % (cc.replace("'", "'\"'\"'"),))
        if data and 'llvm-gcc' in data:
            # Found LLVM-GCC, fall back to clang
            cc = _find_build_tool('clang')
    if not cc:
        raise SystemError(
               "Cannot locate working compiler")
    if cc != oldcc:
        # Found a replacement compiler.
        # Modify config vars using new compiler, if not already explicitly
        # overridden by an env variable, preserving additional arguments.
        for cv in _COMPILER_CONFIG_VARS:
            if cv in _config_vars and cv not in os.environ:
                cv_split = _config_vars[cv].split()
                cv_split[0] = cc if cv != 'CXX' else cc + '++'
                _save_modified_value(_config_vars, cv, ' '.join(cv_split))
    return _config_vars
 def _remove_universal_flags(_config_vars):
    """Remove all universal build arguments from config vars"""
    for cv in _UNIVERSAL_CONFIG_VARS:
        # Do not alter a config var explicitly overridden by env var
        if cv in _config_vars and cv not in os.environ:
            flags = _config_vars[cv]
            flags = re.sub(r'-arch\s+\w+\s', ' ', flags, flags=re.ASCII)
            flags = re.sub('-isysroot [^ \t]*', ' ', flags)
            _save_modified_value(_config_vars, cv, flags)
    return _config_vars
 def _remove_unsupported_archs(_config_vars):
    """Remove any unsupported archs from config vars"""
    # Different Xcode releases support different sets for '-arch'
    # flags. In particular, Xcode 4.x no longer supports the
    # PPC architectures.
    #
    # This code automatically removes '-arch ppc' and '-arch ppc64'
    # when these are not supported. That makes it possible to
    # build extensions on OSX 10.7 and later with the prebuilt
    # 32-bit installer on the python.org website.
    # skip checks if the compiler was overridden with a CC env variable
    if 'CC' in os.environ:
        return _config_vars
    if re.search(r'-arch\s+ppc', _config_vars['CFLAGS']) is not None:
        # NOTE: Cannot use subprocess here because of bootstrap
        # issues when building Python itself
        status = os.system(
            """echo 'int main{};' | """
            """'%s' -c -arch ppc -x c -o /dev/null /dev/null 2>/dev/null"""
            %(_config_vars['CC'].replace("'", "'\"'\"'"),))
        if status:
            # The compile failed for some reason.  Because of differences
            # across Xcode and compiler versions, there is no reliable way
            # to be sure why it failed.  Assume here it was due to lack of
            # PPC support and remove the related '-arch' flags from each
            # config variables not explicitly overridden by an environment
            # variable.  If the error was for some other reason, we hope the
            # failure will show up again when trying to compile an extension
            # module.
            for cv in _UNIVERSAL_CONFIG_VARS:
                if cv in _config_vars and cv not in os.environ:
                    flags = _config_vars[cv]
                    flags = re.sub(r'-arch\s+ppc\w*\s', ' ', flags)
                    _save_modified_value(_config_vars, cv, flags)
    return _config_vars
 def _override_all_archs(_config_vars):
    """Allow override of all archs with ARCHFLAGS env var"""
    # NOTE: This name was introduced by Apple in OSX 10.5 and
    # is used by several scripting languages distributed with
    # that OS release.
    if 'ARCHFLAGS' in os.environ:
        arch = os.environ['ARCHFLAGS']
        for cv in _UNIVERSAL_CONFIG_VARS:
            if cv in _config_vars and '-arch' in _config_vars[cv]:
                flags = _config_vars[cv]
                flags = re.sub(r'-arch\s+\w+\s', ' ', flags)
                flags = flags + ' ' + arch
                _save_modified_value(_config_vars, cv, flags)
    return _config_vars
 def _check_for_unavailable_sdk(_config_vars):
    """Remove references to any SDKs not available"""
    # If we're on OSX 10.5 or later and the user tries to
    # compile an extension using an SDK that is not present
    # on the current machine it is better to not use an SDK
    # than to fail.  This is particularly important with
    # the standalone Command Line Tools alternative to a
    # full-blown Xcode install since the CLT packages do not
    # provide SDKs.  If the SDK is not present, it is assumed
    # that the header files and dev libs have been installed
    # to /usr and /System/Library by either a standalone CLT
    # package or the CLT component within Xcode.
    cflags = _config_vars.get('CFLAGS', '')
    m = re.search(r'-isysroot\s+(\S+)', cflags)
    if m is not None:
        sdk = m.group(1)
        if not os.path.exists(sdk):
            for cv in _UNIVERSAL_CONFIG_VARS:
                # Do not alter a config var explicitly overridden by env var
                if cv in _config_vars and cv not in os.environ:
                    flags = _config_vars[cv]
                    flags = re.sub(r'-isysroot\s+\S+(?:\s|$)', ' ', flags)
                    _save_modified_value(_config_vars, cv, flags)
    return _config_vars
 def compiler_fixup(compiler_so, cc_args):
    """
    This function will strip '-isysroot PATH' and '-arch ARCH' from the
    compile flags if the user has specified one them in extra_compile_flags.
    This is needed because '-arch ARCH' adds another architecture to the
    build, without a way to remove an architecture. Furthermore GCC will
    barf if multiple '-isysroot' arguments are present.
    """
    stripArch = stripSysroot = False
    compiler_so = list(compiler_so)
    if not _supports_universal_builds():
        # OSX before 10.4.0, these don't support -arch and -isysroot at
        # all.
        stripArch = stripSysroot = True
    else:
        stripArch = '-arch' in cc_args
        stripSysroot = '-isysroot' in cc_args
    if stripArch or 'ARCHFLAGS' in os.environ:
        while True:
            try:
                index = compiler_so.index('-arch')
                # Strip this argument and the next one:
                del compiler_so[index:index+2]
            except ValueError:
                break
    if 'ARCHFLAGS' in os.environ and not stripArch:
        # User specified different -arch flags in the environ,
        # see also distutils.sysconfig
        compiler_so = compiler_so + os.environ['ARCHFLAGS'].split()
    if stripSysroot:
        while True:
            try:
                index = compiler_so.index('-isysroot')
                # Strip this argument and the next one:
                del compiler_so[index:index+2]
            except ValueError:
                break
    # Check if the SDK that is used during compilation actually exists,
    # the universal build requires the usage of a universal SDK and not all
    # users have that installed by default.
    sysroot = None
    if '-isysroot' in cc_args:
        idx = cc_args.index('-isysroot')
        sysroot = cc_args[idx+1]
    elif '-isysroot' in compiler_so:
        idx = compiler_so.index('-isysroot')
        sysroot = compiler_so[idx+1]
    if sysroot and not os.path.isdir(sysroot):
        from distutils import log
        log.warn("Compiling with an SDK that doesn't seem to exist: %s",
                sysroot)
        log.warn("Please check your Xcode installation")
    return compiler_so
 def customize_config_vars(_config_vars):
    """Customize Python build configuration variables.
    Called internally from sysconfig with a mutable mapping
    containing name/value pairs parsed from the configured
    makefile used to build this interpreter.  Returns
    the mapping updated as needed to reflect the environment
    in which the interpreter is running; in the case of
    a Python from a binary installer, the installed
    environment may be very different from the build
    environment, i.e. different OS levels, different
    built tools, different available CPU architectures.
    This customization is performed whenever
    distutils.sysconfig.get_config_vars() is first
    called.  It may be used in environments where no
    compilers are present, i.e. when installing pure
    Python dists.  Customization of compiler paths
    and detection of unavailable archs is deferred
    until the first extension module build is
    requested (in distutils.sysconfig.customize_compiler).
    Currently called from distutils.sysconfig
    """
    if not _supports_universal_builds():
        # On Mac OS X before 10.4, check if -arch and -isysroot
        # are in CFLAGS or LDFLAGS and remove them if they are.
        # This is needed when building extensions on a 10.3 system
        # using a universal build of python.
        _remove_universal_flags(_config_vars)
    # Allow user to override all archs with ARCHFLAGS env var
    _override_all_archs(_config_vars)
    # Remove references to sdks that are not found
    _check_for_unavailable_sdk(_config_vars)
    return _config_vars
 def customize_compiler(_config_vars):
    """Customize compiler path and configuration variables.
    This customization is performed when the first
    extension module build is requested
    in distutils.sysconfig.customize_compiler).
    """
    # Find a compiler to use for extension module builds
    _find_appropriate_compiler(_config_vars)
    # Remove ppc arch flags if not supported here
    _remove_unsupported_archs(_config_vars)
    # Allow user to override all archs with ARCHFLAGS env var
    _override_all_archs(_config_vars)
    return _config_vars
 def get_platform_osx(_config_vars, osname, release, machine):
    """Filter values for get_platform()"""
    # called from get_platform() in sysconfig and distutils.util
    #
    # For our purposes, we'll assume that the system version from
    # distutils' perspective is what MACOSX_DEPLOYMENT_TARGET is set
    # to. This makes the compatibility story a bit more sane because the
    # machine is going to compile and link as if it were
    # MACOSX_DEPLOYMENT_TARGET.
    macver = _config_vars.get('MACOSX_DEPLOYMENT_TARGET', '')
    macrelease = _get_system_version() or macver
    macver = macver or macrelease
    if macver:
        release = macver
        osname = "macosx"
        # Use the original CFLAGS value, if available, so that we
        # return the same machine type for the platform string.
        # Otherwise, distutils may consider this a cross-compiling
        # case and disallow installs.
        cflags = _config_vars.get(_INITPRE+'CFLAGS',
                                    _config_vars.get('CFLAGS', ''))
        if macrelease:
            try:
                macrelease = tuple(int(i) for i in macrelease.split('.')[0:2])
            except ValueError:
                macrelease = (10, 0)
        else:
            # assume no universal support
            macrelease = (10, 0)
        if (macrelease >= (10, 4)) and '-arch' in cflags.strip():
            # The universal build will build fat binaries, but not on
            # systems before 10.4
            machine = 'fat'
            archs = re.findall(r'-arch\s+(\S+)', cflags)
            archs = tuple(sorted(set(archs)))
            if len(archs) == 1:
                machine = archs[0]
            elif archs == ('i386', 'ppc'):
                machine = 'fat'
            elif archs == ('i386', 'x86_64'):
                machine = 'intel'
            elif archs == ('i386', 'ppc', 'x86_64'):
                machine = 'fat3'
            elif archs == ('ppc64', 'x86_64'):
                machine = 'fat64'
            elif archs == ('i386', 'ppc', 'ppc64', 'x86_64'):
                machine = 'universal'
            else:
                raise ValueError(
                   "Don't know machine value for archs=%r" % (archs,))
        elif machine == 'i386':
            # On OSX the machine type returned by uname is always the
            # 32-bit variant, even if the executable architecture is
            # the 64-bit variant
            if sys.maxsize >= 2**32:
                machine = 'x86_64'
        elif machine in ('PowerPC', 'Power_Macintosh'):
            # Pick a sane name for the PPC architecture.
            # See 'i386' case
            if sys.maxsize >= 2**32:
                machine = 'ppc64'
            else:
                machine = 'ppc'
    return (osname, release, machine)
--- a/Lib/_py_abc.py
+++ b/Lib/_py_abc.py
@ -0,0 +1,147 @@
 from _weakrefset import WeakSet
 def get_cache_token():
    """Returns the current ABC cache token.
    The token is an opaque object (supporting equality testing) identifying the
    current version of the ABC cache for virtual subclasses. The token changes
    with every call to ``register()`` on any ABC.
    """
    return ABCMeta._abc_invalidation_counter
 class ABCMeta(type):
    """Metaclass for defining Abstract Base Classes (ABCs).
    Use this metaclass to create an ABC.  An ABC can be subclassed
    directly, and then acts as a mix-in class.  You can also register
    unrelated concrete classes (even built-in classes) and unrelated
    ABCs as 'virtual subclasses' -- these and their descendants will
    be considered subclasses of the registering ABC by the built-in
    issubclass() function, but the registering ABC won't show up in
    their MRO (Method Resolution Order) nor will method
    implementations defined by the registering ABC be callable (not
    even via super()).
    """
    # A global counter that is incremented each time a class is
    # registered as a virtual subclass of anything.  It forces the
    # negative cache to be cleared before its next use.
    # Note: this counter is private. Use `abc.get_cache_token()` for
    #       external code.
    _abc_invalidation_counter = 0
    def __new__(mcls, name, bases, namespace, **kwargs):
        cls = super().__new__(mcls, name, bases, namespace, **kwargs)
        # Compute set of abstract method names
        abstracts = {name
                     for name, value in namespace.items()
                     if getattr(value, "__isabstractmethod__", False)}
        for base in bases:
            for name in getattr(base, "__abstractmethods__", set()):
                value = getattr(cls, name, None)
                if getattr(value, "__isabstractmethod__", False):
                    abstracts.add(name)
        cls.__abstractmethods__ = frozenset(abstracts)
        # Set up inheritance registry
        cls._abc_registry = WeakSet()
        cls._abc_cache = WeakSet()
        cls._abc_negative_cache = WeakSet()
        cls._abc_negative_cache_version = ABCMeta._abc_invalidation_counter
        return cls
    def register(cls, subclass):
        """Register a virtual subclass of an ABC.
        Returns the subclass, to allow usage as a class decorator.
        """
        if not isinstance(subclass, type):
            raise TypeError("Can only register classes")
        if issubclass(subclass, cls):
            return subclass  # Already a subclass
        # Subtle: test for cycles *after* testing for "already a subclass";
        # this means we allow X.register(X) and interpret it as a no-op.
        if issubclass(cls, subclass):
            # This would create a cycle, which is bad for the algorithm below
            raise RuntimeError("Refusing to create an inheritance cycle")
        cls._abc_registry.add(subclass)
        ABCMeta._abc_invalidation_counter += 1  # Invalidate negative cache
        return subclass
    def _dump_registry(cls, file=None):
        """Debug helper to print the ABC registry."""
        print(f"Class: {cls.__module__}.{cls.__qualname__}", file=file)
        print(f"Inv. counter: {get_cache_token()}", file=file)
        for name in cls.__dict__:
            if name.startswith("_abc_"):
                value = getattr(cls, name)
                if isinstance(value, WeakSet):
                    value = set(value)
                print(f"{name}: {value!r}", file=file)
    def _abc_registry_clear(cls):
        """Clear the registry (for debugging or testing)."""
        cls._abc_registry.clear()
    def _abc_caches_clear(cls):
        """Clear the caches (for debugging or testing)."""
        cls._abc_cache.clear()
        cls._abc_negative_cache.clear()
    def __instancecheck__(cls, instance):
        """Override for isinstance(instance, cls)."""
        # Inline the cache checking
        subclass = instance.__class__
        if subclass in cls._abc_cache:
            return True
        subtype = type(instance)
        if subtype is subclass:
            if (cls._abc_negative_cache_version ==
                ABCMeta._abc_invalidation_counter and
                subclass in cls._abc_negative_cache):
                return False
            # Fall back to the subclass check.
            return cls.__subclasscheck__(subclass)
        return any(cls.__subclasscheck__(c) for c in (subclass, subtype))
    def __subclasscheck__(cls, subclass):
        """Override for issubclass(subclass, cls)."""
        if not isinstance(subclass, type):
            raise TypeError('issubclass() arg 1 must be a class')
        # Check cache
        if subclass in cls._abc_cache:
            return True
        # Check negative cache; may have to invalidate
        if cls._abc_negative_cache_version < ABCMeta._abc_invalidation_counter:
            # Invalidate the negative cache
            cls._abc_negative_cache = WeakSet()
            cls._abc_negative_cache_version = ABCMeta._abc_invalidation_counter
        elif subclass in cls._abc_negative_cache:
            return False
        # Check the subclass hook
        ok = cls.__subclasshook__(subclass)
        if ok is not NotImplemented:
            assert isinstance(ok, bool)
            if ok:
                cls._abc_cache.add(subclass)
            else:
                cls._abc_negative_cache.add(subclass)
            return ok
        # Check if it's a direct subclass
        if cls in getattr(subclass, '__mro__', ()):
            cls._abc_cache.add(subclass)
            return True
        # Check if it's a subclass of a registered class (recursive)
        for rcls in cls._abc_registry:
            if issubclass(subclass, rcls):
                cls._abc_cache.add(subclass)
                return True
        # Check if it's a subclass of a subclass (recursive)
        for scls in cls.__subclasses__():
            if issubclass(subclass, scls):
                cls._abc_cache.add(subclass)
                return True
        # No dice; update negative cache
        cls._abc_negative_cache.add(subclass)
        return False
--- a/Lib/_pydecimal.py
+++ b/Lib/_pydecimal.py
--- a/Lib/_pyio.py
+++ b/Lib/_pyio.py
--- a/Lib/_sitebuiltins.py
+++ b/Lib/_sitebuiltins.py
@ -0,0 +1,103 @@
 """
 The objects used by the site module to add custom builtins.
 """
 # Those objects are almost immortal and they keep a reference to their module
 # globals.  Defining them in the site module would keep too many references
 # alive.
 # Note this means this module should also avoid keep things alive in its
 # globals.
 import sys
 class Quitter(object):
    def __init__(self, name, eof):
        self.name = name
        self.eof = eof
    def __repr__(self):
        return 'Use %s() or %s to exit' % (self.name, self.eof)
    def __call__(self, code=None):
        # Shells like IDLE catch the SystemExit, but listen when their
        # stdin wrapper is closed.
        try:
            sys.stdin.close()
        except:
            pass
        raise SystemExit(code)
 class _Printer(object):
    """interactive prompt objects for printing the license text, a list of
    contributors and the copyright notice."""
    MAXLINES = 23
    def __init__(self, name, data, files=(), dirs=()):
        import os
        self.__name = name
        self.__data = data
        self.__lines = None
        self.__filenames = [os.path.join(dir, filename)
                            for dir in dirs
                            for filename in files]
    def __setup(self):
        if self.__lines:
            return
        data = None
        for filename in self.__filenames:
            try:
                with open(filename, "r") as fp:
                    data = fp.read()
                break
            except OSError:
                pass
        if not data:
            data = self.__data
        self.__lines = data.split('\n')
        self.__linecnt = len(self.__lines)
    def __repr__(self):
        self.__setup()
        if len(self.__lines) <= self.MAXLINES:
            return "\n".join(self.__lines)
        else:
            return "Type %s() to see the full %s text" % ((self.__name,)*2)
    def __call__(self):
        self.__setup()
        prompt = 'Hit Return for more, or q (and Return) to quit: '
        lineno = 0
        while 1:
            try:
                for i in range(lineno, lineno + self.MAXLINES):
                    print(self.__lines[i])
            except IndexError:
                break
            else:
                lineno += self.MAXLINES
                key = None
                while key is None:
                    key = input(prompt)
                    if key not in ('', 'q'):
                        key = None
                if key == 'q':
                    break
 class _Helper(object):
    """Define the builtin 'help'.
    This is a wrapper around pydoc.help that provides a helpful message
    when 'help' is typed at the Python interactive prompt.
    Calling help() at the Python prompt starts an interactive help session.
    Calling help(thing) prints help for the python object 'thing'.
    """
    def __repr__(self):
        return "Type help() for interactive help, " \
               "or help(object) for help about object."
    def __call__(self, *args, **kwds):
        import pydoc
        return pydoc.help(*args, **kwds)
--- a/Lib/_strptime.py
+++ b/Lib/_strptime.py
@ -0,0 +1,588 @@
 """Strptime-related classes and functions.
 CLASSES:
    LocaleTime -- Discovers and stores locale-specific time information
    TimeRE -- Creates regexes for pattern matching a string of text containing
                time information
 FUNCTIONS:
    _getlang -- Figure out what language is being used for the locale
    strptime -- Calculates the time struct represented by the passed-in string
 """
 import time
 import locale
 import calendar
 from re import compile as re_compile
 from re import IGNORECASE
 from re import escape as re_escape
 from datetime import (date as datetime_date,
                      timedelta as datetime_timedelta,
                      timezone as datetime_timezone)
 from _thread import allocate_lock as _thread_allocate_lock
 __all__ = []
 def _getlang():
    # Figure out what the current language is set to.
    return locale.getlocale(locale.LC_TIME)
 class LocaleTime(object):
    """Stores and handles locale-specific information related to time.
    ATTRIBUTES:
        f_weekday -- full weekday names (7-item list)
        a_weekday -- abbreviated weekday names (7-item list)
        f_month -- full month names (13-item list; dummy value in [0], which
                    is added by code)
        a_month -- abbreviated month names (13-item list, dummy value in
                    [0], which is added by code)
        am_pm -- AM/PM representation (2-item list)
        LC_date_time -- format string for date/time representation (string)
        LC_date -- format string for date representation (string)
        LC_time -- format string for time representation (string)
        timezone -- daylight- and non-daylight-savings timezone representation
                    (2-item list of sets)
        lang -- Language used by instance (2-item tuple)
    """
    def __init__(self):
        """Set all attributes.
        Order of methods called matters for dependency reasons.
        The locale language is set at the offset and then checked again before
        exiting.  This is to make sure that the attributes were not set with a
        mix of information from more than one locale.  This would most likely
        happen when using threads where one thread calls a locale-dependent
        function while another thread changes the locale while the function in
        the other thread is still running.  Proper coding would call for
        locks to prevent changing the locale while locale-dependent code is
        running.  The check here is done in case someone does not think about
        doing this.
        Only other possible issue is if someone changed the timezone and did
        not call tz.tzset .  That is an issue for the programmer, though,
        since changing the timezone is worthless without that call.
        """
        self.lang = _getlang()
        self.__calc_weekday()
        self.__calc_month()
        self.__calc_am_pm()
        self.__calc_timezone()
        self.__calc_date_time()
        if _getlang() != self.lang:
            raise ValueError("locale changed during initialization")
        if time.tzname != self.tzname or time.daylight != self.daylight:
            raise ValueError("timezone changed during initialization")
    def __pad(self, seq, front):
        # Add '' to seq to either the front (is True), else the back.
        seq = list(seq)
        if front:
            seq.insert(0, '')
        else:
            seq.append('')
        return seq
    def __calc_weekday(self):
        # Set self.a_weekday and self.f_weekday using the calendar
        # module.
        a_weekday = [calendar.day_abbr[i].lower() for i in range(7)]
        f_weekday = [calendar.day_name[i].lower() for i in range(7)]
        self.a_weekday = a_weekday
        self.f_weekday = f_weekday
    def __calc_month(self):
        # Set self.f_month and self.a_month using the calendar module.
        a_month = [calendar.month_abbr[i].lower() for i in range(13)]
        f_month = [calendar.month_name[i].lower() for i in range(13)]
        self.a_month = a_month
        self.f_month = f_month
    def __calc_am_pm(self):
        # Set self.am_pm by using time.strftime().
        # The magic date (1999,3,17,hour,44,55,2,76,0) is not really that
        # magical; just happened to have used it everywhere else where a
        # static date was needed.
        am_pm = []
        for hour in (1, 22):
            time_tuple = time.struct_time((1999,3,17,hour,44,55,2,76,0))
            am_pm.append(time.strftime("%p", time_tuple).lower())
        self.am_pm = am_pm
    def __calc_date_time(self):
        # Set self.date_time, self.date, & self.time by using
        # time.strftime().
        # Use (1999,3,17,22,44,55,2,76,0) for magic date because the amount of
        # overloaded numbers is minimized.  The order in which searches for
        # values within the format string is very important; it eliminates
        # possible ambiguity for what something represents.
        time_tuple = time.struct_time((1999,3,17,22,44,55,2,76,0))
        date_time = [None, None, None]
        date_time[0] = time.strftime("%c", time_tuple).lower()
        date_time[1] = time.strftime("%x", time_tuple).lower()
        date_time[2] = time.strftime("%X", time_tuple).lower()
        replacement_pairs = [('%', '%%'), (self.f_weekday[2], '%A'),
                    (self.f_month[3], '%B'), (self.a_weekday[2], '%a'),
                    (self.a_month[3], '%b'), (self.am_pm[1], '%p'),
                    ('1999', '%Y'), ('99', '%y'), ('22', '%H'),
                    ('44', '%M'), ('55', '%S'), ('76', '%j'),
                    ('17', '%d'), ('03', '%m'), ('3', '%m'),
                    # '3' needed for when no leading zero.
                    ('2', '%w'), ('10', '%I')]
        replacement_pairs.extend([(tz, "%Z") for tz_values in self.timezone
                                                for tz in tz_values])
        for offset,directive in ((0,'%c'), (1,'%x'), (2,'%X')):
            current_format = date_time[offset]
            for old, new in replacement_pairs:
                # Must deal with possible lack of locale info
                # manifesting itself as the empty string (e.g., Swedish's
                # lack of AM/PM info) or a platform returning a tuple of empty
                # strings (e.g., MacOS 9 having timezone as ('','')).
                if old:
                    current_format = current_format.replace(old, new)
            # If %W is used, then Sunday, 2005-01-03 will fall on week 0 since
            # 2005-01-03 occurs before the first Monday of the year.  Otherwise
            # %U is used.
            time_tuple = time.struct_time((1999,1,3,1,1,1,6,3,0))
            if '00' in time.strftime(directive, time_tuple):
                U_W = '%W'
            else:
                U_W = '%U'
            date_time[offset] = current_format.replace('11', U_W)
        self.LC_date_time = date_time[0]
        self.LC_date = date_time[1]
        self.LC_time = date_time[2]
    def __calc_timezone(self):
        # Set self.timezone by using time.tzname.
        # Do not worry about possibility of time.tzname[0] == time.tzname[1]
        # and time.daylight; handle that in strptime.
        try:
            time.tzset()
        except AttributeError:
            pass
        self.tzname = time.tzname
        self.daylight = time.daylight
        no_saving = frozenset({"utc", "gmt", self.tzname[0].lower()})
        if self.daylight:
            has_saving = frozenset({self.tzname[1].lower()})
        else:
            has_saving = frozenset()
        self.timezone = (no_saving, has_saving)
 class TimeRE(dict):
    """Handle conversion from format directives to regexes."""
    def __init__(self, locale_time=None):
        """Create keys/values.
        Order of execution is important for dependency reasons.
        """
        if locale_time:
            self.locale_time = locale_time
        else:
            self.locale_time = LocaleTime()
        base = super()
        base.__init__({
            # The " \d" part of the regex is to make %c from ANSI C work
            'd': r"(?P<d>3[0-1]|[1-2]\d|0[1-9]|[1-9]| [1-9])",
            'f': r"(?P<f>[0-9]{1,6})",
            'H': r"(?P<H>2[0-3]|[0-1]\d|\d)",
            'I': r"(?P<I>1[0-2]|0[1-9]|[1-9])",
            'G': r"(?P<G>\d\d\d\d)",
            'j': r"(?P<j>36[0-6]|3[0-5]\d|[1-2]\d\d|0[1-9]\d|00[1-9]|[1-9]\d|0[1-9]|[1-9])",
            'm': r"(?P<m>1[0-2]|0[1-9]|[1-9])",
            'M': r"(?P<M>[0-5]\d|\d)",
            'S': r"(?P<S>6[0-1]|[0-5]\d|\d)",
            'U': r"(?P<U>5[0-3]|[0-4]\d|\d)",
            'w': r"(?P<w>[0-6])",
            'u': r"(?P<u>[1-7])",
            'V': r"(?P<V>5[0-3]|0[1-9]|[1-4]\d|\d)",
            # W is set below by using 'U'
            'y': r"(?P<y>\d\d)",
            #XXX: Does 'Y' need to worry about having less or more than
            #     4 digits?
            'Y': r"(?P<Y>\d\d\d\d)",
            'z': r"(?P<z>[+-]\d\d:?[0-5]\d(:?[0-5]\d(\.\d{1,6})?)?|Z)",
            'A': self.__seqToRE(self.locale_time.f_weekday, 'A'),
            'a': self.__seqToRE(self.locale_time.a_weekday, 'a'),
            'B': self.__seqToRE(self.locale_time.f_month[1:], 'B'),
            'b': self.__seqToRE(self.locale_time.a_month[1:], 'b'),
            'p': self.__seqToRE(self.locale_time.am_pm, 'p'),
            'Z': self.__seqToRE((tz for tz_names in self.locale_time.timezone
                                        for tz in tz_names),
                                'Z'),
            '%': '%'})
        base.__setitem__('W', base.__getitem__('U').replace('U', 'W'))
        base.__setitem__('c', self.pattern(self.locale_time.LC_date_time))
        base.__setitem__('x', self.pattern(self.locale_time.LC_date))
        base.__setitem__('X', self.pattern(self.locale_time.LC_time))
    def __seqToRE(self, to_convert, directive):
        """Convert a list to a regex string for matching a directive.
        Want possible matching values to be from longest to shortest.  This
        prevents the possibility of a match occurring for a value that also
        a substring of a larger value that should have matched (e.g., 'abc'
        matching when 'abcdef' should have been the match).
        """
        to_convert = sorted(to_convert, key=len, reverse=True)
        for value in to_convert:
            if value != '':
                break
        else:
            return ''
        regex = '|'.join(re_escape(stuff) for stuff in to_convert)
        regex = '(?P<%s>%s' % (directive, regex)
        return '%s)' % regex
    def pattern(self, format):
        """Return regex pattern for the format string.
        Need to make sure that any characters that might be interpreted as
        regex syntax are escaped.
        """
        processed_format = ''
        # The sub() call escapes all characters that might be misconstrued
        # as regex syntax.  Cannot use re.escape since we have to deal with
        # format directives (%m, etc.).
        regex_chars = re_compile(r"([\\.^$*+?\(\){}\[\]|])")
        format = regex_chars.sub(r"\\\1", format)
        whitespace_replacement = re_compile(r'\s+')
        format = whitespace_replacement.sub(r'\\s+', format)
        while '%' in format:
            directive_index = format.index('%')+1
            processed_format = "%s%s%s" % (processed_format,
                                           format[:directive_index-1],
                                           self[format[directive_index]])
            format = format[directive_index+1:]
        return "%s%s" % (processed_format, format)
    def compile(self, format):
        """Return a compiled re object for the format string."""
        return re_compile(self.pattern(format), IGNORECASE)
 _cache_lock = _thread_allocate_lock()
 # DO NOT modify _TimeRE_cache or _regex_cache without acquiring the cache lock
 # first!
 _TimeRE_cache = TimeRE()
 _CACHE_MAX_SIZE = 5 # Max number of regexes stored in _regex_cache
 _regex_cache = {}
 def _calc_julian_from_U_or_W(year, week_of_year, day_of_week, week_starts_Mon):
    """Calculate the Julian day based on the year, week of the year, and day of
    the week, with week_start_day representing whether the week of the year
    assumes the week starts on Sunday or Monday (6 or 0)."""
    first_weekday = datetime_date(year, 1, 1).weekday()
    # If we are dealing with the %U directive (week starts on Sunday), it's
    # easier to just shift the view to Sunday being the first day of the
    # week.
    if not week_starts_Mon:
        first_weekday = (first_weekday + 1) % 7
        day_of_week = (day_of_week + 1) % 7
    # Need to watch out for a week 0 (when the first day of the year is not
    # the same as that specified by %U or %W).
    week_0_length = (7 - first_weekday) % 7
    if week_of_year == 0:
        return 1 + day_of_week - first_weekday
    else:
        days_to_week = week_0_length + (7 * (week_of_year - 1))
        return 1 + days_to_week + day_of_week
 def _calc_julian_from_V(iso_year, iso_week, iso_weekday):
    """Calculate the Julian day based on the ISO 8601 year, week, and weekday.
    ISO weeks start on Mondays, with week 01 being the week containing 4 Jan.
    ISO week days range from 1 (Monday) to 7 (Sunday).
    """
    correction = datetime_date(iso_year, 1, 4).isoweekday() + 3
    ordinal = (iso_week * 7) + iso_weekday - correction
    # ordinal may be negative or 0 now, which means the date is in the previous
    # calendar year
    if ordinal < 1:
        ordinal += datetime_date(iso_year, 1, 1).toordinal()
        iso_year -= 1
        ordinal -= datetime_date(iso_year, 1, 1).toordinal()
    return iso_year, ordinal
 def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"):
    """Return a 2-tuple consisting of a time struct and an int containing
    the number of microseconds based on the input string and the
    format string."""
    for index, arg in enumerate([data_string, format]):
        if not isinstance(arg, str):
            msg = "strptime() argument {} must be str, not {}"
            raise TypeError(msg.format(index, type(arg)))
    global _TimeRE_cache, _regex_cache
    with _cache_lock:
        locale_time = _TimeRE_cache.locale_time
        if (_getlang() != locale_time.lang or
            time.tzname != locale_time.tzname or
            time.daylight != locale_time.daylight):
            _TimeRE_cache = TimeRE()
            _regex_cache.clear()
            locale_time = _TimeRE_cache.locale_time
        if len(_regex_cache) > _CACHE_MAX_SIZE:
            _regex_cache.clear()
        format_regex = _regex_cache.get(format)
        if not format_regex:
            try:
                format_regex = _TimeRE_cache.compile(format)
            # KeyError raised when a bad format is found; can be specified as
            # \\, in which case it was a stray % but with a space after it
            except KeyError as err:
                bad_directive = err.args[0]
                if bad_directive == "\\":
                    bad_directive = "%"
                del err
                raise ValueError("'%s' is a bad directive in format '%s'" %
                                    (bad_directive, format)) from None
            # IndexError only occurs when the format string is "%"
            except IndexError:
                raise ValueError("stray %% in format '%s'" % format) from None
            _regex_cache[format] = format_regex
    found = format_regex.match(data_string)
    if not found:
        raise ValueError("time data %r does not match format %r" %
                         (data_string, format))
    if len(data_string) != found.end():
        raise ValueError("unconverted data remains: %s" %
                          data_string[found.end():])
    iso_year = year = None
    month = day = 1
    hour = minute = second = fraction = 0
    tz = -1
    gmtoff = None
    gmtoff_fraction = 0
    # Default to -1 to signify that values not known; not critical to have,
    # though
    iso_week = week_of_year = None
    week_of_year_start = None
    # weekday and julian defaulted to None so as to signal need to calculate
    # values
    weekday = julian = None
    found_dict = found.groupdict()
    for group_key in found_dict.keys():
        # Directives not explicitly handled below:
        #   c, x, X
        #      handled by making out of other directives
        #   U, W
        #      worthless without day of the week
        if group_key == 'y':
            year = int(found_dict['y'])
            # Open Group specification for strptime() states that a %y
            #value in the range of [00, 68] is in the century 2000, while
            #[69,99] is in the century 1900
            if year <= 68:
                year += 2000
            else:
                year += 1900
        elif group_key == 'Y':
            year = int(found_dict['Y'])
        elif group_key == 'G':
            iso_year = int(found_dict['G'])
        elif group_key == 'm':
            month = int(found_dict['m'])
        elif group_key == 'B':
            month = locale_time.f_month.index(found_dict['B'].lower())
        elif group_key == 'b':
            month = locale_time.a_month.index(found_dict['b'].lower())
        elif group_key == 'd':
            day = int(found_dict['d'])
        elif group_key == 'H':
            hour = int(found_dict['H'])
        elif group_key == 'I':
            hour = int(found_dict['I'])
            ampm = found_dict.get('p', '').lower()
            # If there was no AM/PM indicator, we'll treat this like AM
            if ampm in ('', locale_time.am_pm[0]):
                # We're in AM so the hour is correct unless we're
                # looking at 12 midnight.
                # 12 midnight == 12 AM == hour 0
                if hour == 12:
                    hour = 0
            elif ampm == locale_time.am_pm[1]:
                # We're in PM so we need to add 12 to the hour unless
                # we're looking at 12 noon.
                # 12 noon == 12 PM == hour 12
                if hour != 12:
                    hour += 12
        elif group_key == 'M':
            minute = int(found_dict['M'])
        elif group_key == 'S':
            second = int(found_dict['S'])
        elif group_key == 'f':
            s = found_dict['f']
            # Pad to always return microseconds.
            s += "0" * (6 - len(s))
            fraction = int(s)
        elif group_key == 'A':
            weekday = locale_time.f_weekday.index(found_dict['A'].lower())
        elif group_key == 'a':
            weekday = locale_time.a_weekday.index(found_dict['a'].lower())
        elif group_key == 'w':
            weekday = int(found_dict['w'])
            if weekday == 0:
                weekday = 6
            else:
                weekday -= 1
        elif group_key == 'u':
            weekday = int(found_dict['u'])
            weekday -= 1
        elif group_key == 'j':
            julian = int(found_dict['j'])
        elif group_key in ('U', 'W'):
            week_of_year = int(found_dict[group_key])
            if group_key == 'U':
                # U starts week on Sunday.
                week_of_year_start = 6
            else:
                # W starts week on Monday.
                week_of_year_start = 0
        elif group_key == 'V':
            iso_week = int(found_dict['V'])
        elif group_key == 'z':
            z = found_dict['z']
            if z == 'Z':
                gmtoff = 0
            else:
                if z[3] == ':':
                    z = z[:3] + z[4:]
                    if len(z) > 5:
                        if z[5] != ':':
                            msg = f"Inconsistent use of : in {found_dict['z']}"
                            raise ValueError(msg)
                        z = z[:5] + z[6:]
                hours = int(z[1:3])
                minutes = int(z[3:5])
                seconds = int(z[5:7] or 0)
                gmtoff = (hours * 60 * 60) + (minutes * 60) + seconds
                gmtoff_remainder = z[8:]
                # Pad to always return microseconds.
                gmtoff_remainder_padding = "0" * (6 - len(gmtoff_remainder))
                gmtoff_fraction = int(gmtoff_remainder + gmtoff_remainder_padding)
                if z.startswith("-"):
                    gmtoff = -gmtoff
                    gmtoff_fraction = -gmtoff_fraction
        elif group_key == 'Z':
            # Since -1 is default value only need to worry about setting tz if
            # it can be something other than -1.
            found_zone = found_dict['Z'].lower()
            for value, tz_values in enumerate(locale_time.timezone):
                if found_zone in tz_values:
                    # Deal with bad locale setup where timezone names are the
                    # same and yet time.daylight is true; too ambiguous to
                    # be able to tell what timezone has daylight savings
                    if (time.tzname[0] == time.tzname[1] and
                       time.daylight and found_zone not in ("utc", "gmt")):
                        break
                    else:
                        tz = value
                        break
    # Deal with the cases where ambiguities arize
    # don't assume default values for ISO week/year
    if year is None and iso_year is not None:
        if iso_week is None or weekday is None:
            raise ValueError("ISO year directive '%G' must be used with "
                             "the ISO week directive '%V' and a weekday "
                             "directive ('%A', '%a', '%w', or '%u').")
        if julian is not None:
            raise ValueError("Day of the year directive '%j' is not "
                             "compatible with ISO year directive '%G'. "
                             "Use '%Y' instead.")
    elif week_of_year is None and iso_week is not None:
        if weekday is None:
            raise ValueError("ISO week directive '%V' must be used with "
                             "the ISO year directive '%G' and a weekday "
                             "directive ('%A', '%a', '%w', or '%u').")
        else:
            raise ValueError("ISO week directive '%V' is incompatible with "
                             "the year directive '%Y'. Use the ISO year '%G' "
                             "instead.")
    leap_year_fix = False
    if year is None and month == 2 and day == 29:
        year = 1904  # 1904 is first leap year of 20th century
        leap_year_fix = True
    elif year is None:
        year = 1900
    # If we know the week of the year and what day of that week, we can figure
    # out the Julian day of the year.
    if julian is None and weekday is not None:
        if week_of_year is not None:
            week_starts_Mon = True if week_of_year_start == 0 else False
            julian = _calc_julian_from_U_or_W(year, week_of_year, weekday,
                                                week_starts_Mon)
        elif iso_year is not None and iso_week is not None:
            year, julian = _calc_julian_from_V(iso_year, iso_week, weekday + 1)
        if julian is not None and julian <= 0:
            year -= 1
            yday = 366 if calendar.isleap(year) else 365
            julian += yday
    if julian is None:
        # Cannot pre-calculate datetime_date() since can change in Julian
        # calculation and thus could have different value for the day of
        # the week calculation.
        # Need to add 1 to result since first day of the year is 1, not 0.
        julian = datetime_date(year, month, day).toordinal() - \
                  datetime_date(year, 1, 1).toordinal() + 1
    else:  # Assume that if they bothered to include Julian day (or if it was
           # calculated above with year/week/weekday) it will be accurate.
        datetime_result = datetime_date.fromordinal(
                            (julian - 1) +
                            datetime_date(year, 1, 1).toordinal())
        year = datetime_result.year
        month = datetime_result.month
        day = datetime_result.day
    if weekday is None:
        weekday = datetime_date(year, month, day).weekday()
    # Add timezone info
    tzname = found_dict.get("Z")
    if leap_year_fix:
        # the caller didn't supply a year but asked for Feb 29th. We couldn't
        # use the default of 1900 for computations. We set it back to ensure
        # that February 29th is smaller than March 1st.
        year = 1900
    return (year, month, day,
            hour, minute, second,
            weekday, julian, tz, tzname, gmtoff), fraction, gmtoff_fraction
 def _strptime_time(data_string, format="%a %b %d %H:%M:%S %Y"):
    """Return a time struct based on the input string and the
    format string."""
    tt = _strptime(data_string, format)[0]
    return time.struct_time(tt[:time._STRUCT_TM_ITEMS])
 def _strptime_datetime(cls, data_string, format="%a %b %d %H:%M:%S %Y"):
    """Return a class cls instance based on the input string and the
    format string."""
    tt, fraction, gmtoff_fraction = _strptime(data_string, format)
    tzname, gmtoff = tt[-2:]
    args = tt[:6] + (fraction,)
    if gmtoff is not None:
        tzdelta = datetime_timedelta(seconds=gmtoff, microseconds=gmtoff_fraction)
        if tzname:
            tz = datetime_timezone(tzdelta, tzname)
        else:
            tz = datetime_timezone(tzdelta)
        args += (tz,)
    return cls(*args)
--- a/Lib/_threading_local.py
+++ b/Lib/_threading_local.py
@ -0,0 +1,242 @@
 """Thread-local objects.
 (Note that this module provides a Python version of the threading.local
 class.  Depending on the version of Python you're using, there may be a
 faster one available.  You should always import the `local` class from
 `threading`.)
 Thread-local objects support the management of thread-local data.
 If you have data that you want to be local to a thread, simply create
 a thread-local object and use its attributes:
  >>> mydata = local()
  >>> mydata.number = 42
  >>> mydata.number
  42
 You can also access the local-object's dictionary:
  >>> mydata.__dict__
  {'number': 42}
  >>> mydata.__dict__.setdefault('widgets', [])
  []
  >>> mydata.widgets
  []
 What's important about thread-local objects is that their data are
 local to a thread. If we access the data in a different thread:
  >>> log = []
  >>> def f():
  ...     items = sorted(mydata.__dict__.items())
  ...     log.append(items)
  ...     mydata.number = 11
  ...     log.append(mydata.number)
  >>> import threading
  >>> thread = threading.Thread(target=f)
  >>> thread.start()
  >>> thread.join()
  >>> log
  [[], 11]
 we get different data.  Furthermore, changes made in the other thread
 don't affect data seen in this thread:
  >>> mydata.number
  42
 Of course, values you get from a local object, including a __dict__
 attribute, are for whatever thread was current at the time the
 attribute was read.  For that reason, you generally don't want to save
 these values across threads, as they apply only to the thread they
 came from.
 You can create custom local objects by subclassing the local class:
  >>> class MyLocal(local):
  ...     number = 2
  ...     def __init__(self, **kw):
  ...         self.__dict__.update(kw)
  ...     def squared(self):
  ...         return self.number ** 2
 This can be useful to support default values, methods and
 initialization.  Note that if you define an __init__ method, it will be
 called each time the local object is used in a separate thread.  This
 is necessary to initialize each thread's dictionary.
 Now if we create a local object:
  >>> mydata = MyLocal(color='red')
 Now we have a default number:
  >>> mydata.number
  2
 an initial color:
  >>> mydata.color
  'red'
  >>> del mydata.color
 And a method that operates on the data:
  >>> mydata.squared()
  4
 As before, we can access the data in a separate thread:
  >>> log = []
  >>> thread = threading.Thread(target=f)
  >>> thread.start()
  >>> thread.join()
  >>> log
  [[('color', 'red')], 11]
 without affecting this thread's data:
  >>> mydata.number
  2
  >>> mydata.color
  Traceback (most recent call last):
  ...
  AttributeError: 'MyLocal' object has no attribute 'color'
 Note that subclasses can define slots, but they are not thread
 local. They are shared across threads:
  >>> class MyLocal(local):
  ...     __slots__ = 'number'
  >>> mydata = MyLocal()
  >>> mydata.number = 42
  >>> mydata.color = 'red'
 So, the separate thread:
  >>> thread = threading.Thread(target=f)
  >>> thread.start()
  >>> thread.join()
 affects what we see:
  >>> mydata.number
  11
 >>> del mydata
 """
 from weakref import ref
 from contextlib import contextmanager
 __all__ = ["local"]
 # We need to use objects from the threading module, but the threading
 # module may also want to use our `local` class, if support for locals
 # isn't compiled in to the `thread` module.  This creates potential problems
 # with circular imports.  For that reason, we don't import `threading`
 # until the bottom of this file (a hack sufficient to worm around the
 # potential problems).  Note that all platforms on CPython do have support
 # for locals in the `thread` module, and there is no circular import problem
 # then, so problems introduced by fiddling the order of imports here won't
 # manifest.
 class _localimpl:
    """A class managing thread-local dicts"""
    __slots__ = 'key', 'dicts', 'localargs', 'locallock', '__weakref__'
    def __init__(self):
        # The key used in the Thread objects' attribute dicts.
        # We keep it a string for speed but make it unlikely to clash with
        # a "real" attribute.
        self.key = '_threading_local._localimpl.' + str(id(self))
        # { id(Thread) -> (ref(Thread), thread-local dict) }
        self.dicts = {}
    def get_dict(self):
        """Return the dict for the current thread. Raises KeyError if none
        defined."""
        thread = current_thread()
        return self.dicts[id(thread)][1]
    def create_dict(self):
        """Create a new dict for the current thread, and return it."""
        localdict = {}
        key = self.key
        thread = current_thread()
        idt = id(thread)
        def local_deleted(_, key=key):
            # When the localimpl is deleted, remove the thread attribute.
            thread = wrthread()
            if thread is not None:
                del thread.__dict__[key]
        def thread_deleted(_, idt=idt):
            # When the thread is deleted, remove the local dict.
            # Note that this is suboptimal if the thread object gets
            # caught in a reference loop. We would like to be called
            # as soon as the OS-level thread ends instead.
            local = wrlocal()
            if local is not None:
                dct = local.dicts.pop(idt)
        wrlocal = ref(self, local_deleted)
        wrthread = ref(thread, thread_deleted)
        thread.__dict__[key] = wrlocal
        self.dicts[idt] = wrthread, localdict
        return localdict
@contextmanager
 def _patch(self):
    impl = object.__getattribute__(self, '_local__impl')
    try:
        dct = impl.get_dict()
    except KeyError:
        dct = impl.create_dict()
        args, kw = impl.localargs
        self.__init__(*args, **kw)
    with impl.locallock:
        object.__setattr__(self, '__dict__', dct)
        yield
 class local:
    __slots__ = '_local__impl', '__dict__'
    def __new__(cls, *args, **kw):
        if (args or kw) and (cls.__init__ is object.__init__):
            raise TypeError("Initialization arguments are not supported")
        self = object.__new__(cls)
        impl = _localimpl()
        impl.localargs = (args, kw)
        impl.locallock = RLock()
        object.__setattr__(self, '_local__impl', impl)
        # We need to create the thread dict in anticipation of
        # __init__ being called, to make sure we don't call it
        # again ourselves.
        impl.create_dict()
        return self
    def __getattribute__(self, name):
        with _patch(self):
            return object.__getattribute__(self, name)
    def __setattr__(self, name, value):
        if name == '__dict__':
            raise AttributeError(
                "%r object attribute '__dict__' is read-only"
                % self.__class__.__name__)
        with _patch(self):
            return object.__setattr__(self, name, value)
    def __delattr__(self, name):
        if name == '__dict__':
            raise AttributeError(
                "%r object attribute '__dict__' is read-only"
                % self.__class__.__name__)
        with _patch(self):
            return object.__delattr__(self, name)
 from threading import current_thread, RLock
--- a/Lib/_weakrefset.py
+++ b/Lib/_weakrefset.py
@ -0,0 +1,196 @@
 # Access WeakSet through the weakref module.
 # This code is separated-out because it is needed
 # by abc.py to load everything else at startup.
 from _weakref import ref
 __all__ = ['WeakSet']
 class _IterationGuard:
    # This context manager registers itself in the current iterators of the
    # weak container, such as to delay all removals until the context manager
    # exits.
    # This technique should be relatively thread-safe (since sets are).
    def __init__(self, weakcontainer):
        # Don't create cycles
        self.weakcontainer = ref(weakcontainer)
    def __enter__(self):
        w = self.weakcontainer()
        if w is not None:
            w._iterating.add(self)
        return self
    def __exit__(self, e, t, b):
        w = self.weakcontainer()
        if w is not None:
            s = w._iterating
            s.remove(self)
            if not s:
                w._commit_removals()
 class WeakSet:
    def __init__(self, data=None):
        self.data = set()
        def _remove(item, selfref=ref(self)):
            self = selfref()
            if self is not None:
                if self._iterating:
                    self._pending_removals.append(item)
                else:
                    self.data.discard(item)
        self._remove = _remove
        # A list of keys to be removed
        self._pending_removals = []
        self._iterating = set()
        if data is not None:
            self.update(data)
    def _commit_removals(self):
        l = self._pending_removals
        discard = self.data.discard
        while l:
            discard(l.pop())
    def __iter__(self):
        with _IterationGuard(self):
            for itemref in self.data:
                item = itemref()
                if item is not None:
                    # Caveat: the iterator will keep a strong reference to
                    # `item` until it is resumed or closed.
                    yield item
    def __len__(self):
        return len(self.data) - len(self._pending_removals)
    def __contains__(self, item):
        try:
            wr = ref(item)
        except TypeError:
            return False
        return wr in self.data
    def __reduce__(self):
        return (self.__class__, (list(self),),
                getattr(self, '__dict__', None))
    def add(self, item):
        if self._pending_removals:
            self._commit_removals()
        self.data.add(ref(item, self._remove))
    def clear(self):
        if self._pending_removals:
            self._commit_removals()
        self.data.clear()
    def copy(self):
        return self.__class__(self)
    def pop(self):
        if self._pending_removals:
            self._commit_removals()
        while True:
            try:
                itemref = self.data.pop()
            except KeyError:
                raise KeyError('pop from empty WeakSet') from None
            item = itemref()
            if item is not None:
                return item
    def remove(self, item):
        if self._pending_removals:
            self._commit_removals()
        self.data.remove(ref(item))
    def discard(self, item):
        if self._pending_removals:
            self._commit_removals()
        self.data.discard(ref(item))
    def update(self, other):
        if self._pending_removals:
            self._commit_removals()
        for element in other:
            self.add(element)
    def __ior__(self, other):
        self.update(other)
        return self
    def difference(self, other):
        newset = self.copy()
        newset.difference_update(other)
        return newset
    __sub__ = difference
    def difference_update(self, other):
        self.__isub__(other)
    def __isub__(self, other):
        if self._pending_removals:
            self._commit_removals()
        if self is other:
            self.data.clear()
        else:
            self.data.difference_update(ref(item) for item in other)
        return self
    def intersection(self, other):
        return self.__class__(item for item in other if item in self)
    __and__ = intersection
    def intersection_update(self, other):
        self.__iand__(other)
    def __iand__(self, other):
        if self._pending_removals:
            self._commit_removals()
        self.data.intersection_update(ref(item) for item in other)
        return self
    def issubset(self, other):
        return self.data.issubset(ref(item) for item in other)
    __le__ = issubset
    def __lt__(self, other):
        return self.data < set(map(ref, other))
    def issuperset(self, other):
        return self.data.issuperset(ref(item) for item in other)
    __ge__ = issuperset
    def __gt__(self, other):
        return self.data > set(map(ref, other))
    def __eq__(self, other):
        if not isinstance(other, self.__class__):
            return NotImplemented
        return self.data == set(map(ref, other))
    def symmetric_difference(self, other):
        newset = self.copy()
        newset.symmetric_difference_update(other)
        return newset
    __xor__ = symmetric_difference
    def symmetric_difference_update(self, other):
        self.__ixor__(other)
    def __ixor__(self, other):
        if self._pending_removals:
            self._commit_removals()
        if self is other:
            self.data.clear()
        else:
            self.data.symmetric_difference_update(ref(item, self._remove) for item in other)
        return self
    def union(self, other):
        return self.__class__(e for s in (self, other) for e in s)
    __or__ = union
    def isdisjoint(self, other):
        return len(self.intersection(other)) == 0
--- a/Lib/abc.py
+++ b/Lib/abc.py
@ -0,0 +1,170 @@
 # Copyright 2007 Google, Inc. All Rights Reserved.
 # Licensed to PSF under a Contributor Agreement.
 """Abstract Base Classes (ABCs) according to PEP 3119."""
 def abstractmethod(funcobj):
    """A decorator indicating abstract methods.
    Requires that the metaclass is ABCMeta or derived from it.  A
    class that has a metaclass derived from ABCMeta cannot be
    instantiated unless all of its abstract methods are overridden.
    The abstract methods can be called using any of the normal
    'super' call mechanisms.
    Usage:
        class C(metaclass=ABCMeta):
            @abstractmethod
            def my_abstract_method(self, ...):
                ...
    """
    funcobj.__isabstractmethod__ = True
    return funcobj
 class abstractclassmethod(classmethod):
    """A decorator indicating abstract classmethods.
    Similar to abstractmethod.
    Usage:
        class C(metaclass=ABCMeta):
            @abstractclassmethod
            def my_abstract_classmethod(cls, ...):
                ...
    'abstractclassmethod' is deprecated. Use 'classmethod' with
    'abstractmethod' instead.
    """
    __isabstractmethod__ = True
    def __init__(self, callable):
        callable.__isabstractmethod__ = True
        super().__init__(callable)
 class abstractstaticmethod(staticmethod):
    """A decorator indicating abstract staticmethods.
    Similar to abstractmethod.
    Usage:
        class C(metaclass=ABCMeta):
            @abstractstaticmethod
            def my_abstract_staticmethod(...):
                ...
    'abstractstaticmethod' is deprecated. Use 'staticmethod' with
    'abstractmethod' instead.
    """
    __isabstractmethod__ = True
    def __init__(self, callable):
        callable.__isabstractmethod__ = True
        super().__init__(callable)
 class abstractproperty(property):
    """A decorator indicating abstract properties.
    Requires that the metaclass is ABCMeta or derived from it.  A
    class that has a metaclass derived from ABCMeta cannot be
    instantiated unless all of its abstract properties are overridden.
    The abstract properties can be called using any of the normal
    'super' call mechanisms.
    Usage:
        class C(metaclass=ABCMeta):
            @abstractproperty
            def my_abstract_property(self):
                ...
    This defines a read-only property; you can also define a read-write
    abstract property using the 'long' form of property declaration:
        class C(metaclass=ABCMeta):
            def getx(self): ...
            def setx(self, value): ...
            x = abstractproperty(getx, setx)
    'abstractproperty' is deprecated. Use 'property' with 'abstractmethod'
    instead.
    """
    __isabstractmethod__ = True
 try:
    from _abc import (get_cache_token, _abc_init, _abc_register,
                      _abc_instancecheck, _abc_subclasscheck, _get_dump,
                      _reset_registry, _reset_caches)
 except ImportError:
    from _py_abc import ABCMeta, get_cache_token
    ABCMeta.__module__ = 'abc'
 else:
    class ABCMeta(type):
        """Metaclass for defining Abstract Base Classes (ABCs).
        Use this metaclass to create an ABC.  An ABC can be subclassed
        directly, and then acts as a mix-in class.  You can also register
        unrelated concrete classes (even built-in classes) and unrelated
        ABCs as 'virtual subclasses' -- these and their descendants will
        be considered subclasses of the registering ABC by the built-in
        issubclass() function, but the registering ABC won't show up in
        their MRO (Method Resolution Order) nor will method
        implementations defined by the registering ABC be callable (not
        even via super()).
        """
        def __new__(mcls, name, bases, namespace, **kwargs):
            cls = super().__new__(mcls, name, bases, namespace, **kwargs)
            _abc_init(cls)
            return cls
        def register(cls, subclass):
            """Register a virtual subclass of an ABC.
            Returns the subclass, to allow usage as a class decorator.
            """
            return _abc_register(cls, subclass)
        def __instancecheck__(cls, instance):
            """Override for isinstance(instance, cls)."""
            return _abc_instancecheck(cls, instance)
        def __subclasscheck__(cls, subclass):
            """Override for issubclass(subclass, cls)."""
            return _abc_subclasscheck(cls, subclass)
        def _dump_registry(cls, file=None):
            """Debug helper to print the ABC registry."""
            print(f"Class: {cls.__module__}.{cls.__qualname__}", file=file)
            print(f"Inv. counter: {get_cache_token()}", file=file)
            (_abc_registry, _abc_cache, _abc_negative_cache,
             _abc_negative_cache_version) = _get_dump(cls)
            print(f"_abc_registry: {_abc_registry!r}", file=file)
            print(f"_abc_cache: {_abc_cache!r}", file=file)
            print(f"_abc_negative_cache: {_abc_negative_cache!r}", file=file)
            print(f"_abc_negative_cache_version: {_abc_negative_cache_version!r}",
                  file=file)
        def _abc_registry_clear(cls):
            """Clear the registry (for debugging or testing)."""
            _reset_registry(cls)
        def _abc_caches_clear(cls):
            """Clear the caches (for debugging or testing)."""
            _reset_caches(cls)
 class ABC(metaclass=ABCMeta):
    """Helper class that provides a standard way to create an ABC using
    inheritance.
    """
    __slots__ = ()
--- a/Lib/aifc.py
+++ b/Lib/aifc.py
@ -0,0 +1,951 @@
 """Stuff to parse AIFF-C and AIFF files.
 Unless explicitly stated otherwise, the description below is true
 both for AIFF-C files and AIFF files.
 An AIFF-C file has the following structure.
  +-----------------+
  | FORM            |
  +-----------------+
  | <size>          |
  +----+------------+
  |    | AIFC       |
  |    +------------+
  |    | <chunks>   |
  |    |    .       |
  |    |    .       |
  |    |    .       |
  +----+------------+
 An AIFF file has the string "AIFF" instead of "AIFC".
 A chunk consists of an identifier (4 bytes) followed by a size (4 bytes,
 big endian order), followed by the data.  The size field does not include
 the size of the 8 byte header.
 The following chunk types are recognized.
  FVER
      <version number of AIFF-C defining document> (AIFF-C only).
  MARK
      <# of markers> (2 bytes)
      list of markers:
          <marker ID> (2 bytes, must be > 0)
          <position> (4 bytes)
          <marker name> ("pstring")
  COMM
      <# of channels> (2 bytes)
      <# of sound frames> (4 bytes)
      <size of the samples> (2 bytes)
      <sampling frequency> (10 bytes, IEEE 80-bit extended
          floating point)
      in AIFF-C files only:
      <compression type> (4 bytes)
      <human-readable version of compression type> ("pstring")
  SSND
      <offset> (4 bytes, not used by this program)
      <blocksize> (4 bytes, not used by this program)
      <sound data>
 A pstring consists of 1 byte length, a string of characters, and 0 or 1
 byte pad to make the total length even.
 Usage.
 Reading AIFF files:
  f = aifc.open(file, 'r')
 where file is either the name of a file or an open file pointer.
 The open file pointer must have methods read(), seek(), and close().
 In some types of audio files, if the setpos() method is not used,
 the seek() method is not necessary.
 This returns an instance of a class with the following public methods:
  getnchannels()  -- returns number of audio channels (1 for
             mono, 2 for stereo)
  getsampwidth()  -- returns sample width in bytes
  getframerate()  -- returns sampling frequency
  getnframes()    -- returns number of audio frames
  getcomptype()   -- returns compression type ('NONE' for AIFF files)
  getcompname()   -- returns human-readable version of
             compression type ('not compressed' for AIFF files)
  getparams() -- returns a namedtuple consisting of all of the
             above in the above order
  getmarkers()    -- get the list of marks in the audio file or None
             if there are no marks
  getmark(id) -- get mark with the specified id (raises an error
             if the mark does not exist)
  readframes(n)   -- returns at most n frames of audio
  rewind()    -- rewind to the beginning of the audio stream
  setpos(pos) -- seek to the specified position
  tell()      -- return the current position
  close()     -- close the instance (make it unusable)
 The position returned by tell(), the position given to setpos() and
 the position of marks are all compatible and have nothing to do with
 the actual position in the file.
 The close() method is called automatically when the class instance
 is destroyed.
 Writing AIFF files:
  f = aifc.open(file, 'w')
 where file is either the name of a file or an open file pointer.
 The open file pointer must have methods write(), tell(), seek(), and
 close().
 This returns an instance of a class with the following public methods:
  aiff()      -- create an AIFF file (AIFF-C default)
  aifc()      -- create an AIFF-C file
  setnchannels(n) -- set the number of channels
  setsampwidth(n) -- set the sample width
  setframerate(n) -- set the frame rate
  setnframes(n)   -- set the number of frames
  setcomptype(type, name)
          -- set the compression type and the
             human-readable compression type
  setparams(tuple)
          -- set all parameters at once
  setmark(id, pos, name)
          -- add specified mark to the list of marks
  tell()      -- return current position in output file (useful
             in combination with setmark())
  writeframesraw(data)
          -- write audio frames without pathing up the
             file header
  writeframes(data)
          -- write audio frames and patch up the file header
  close()     -- patch up the file header and close the
             output file
 You should set the parameters before the first writeframesraw or
 writeframes.  The total number of frames does not need to be set,
 but when it is set to the correct value, the header does not have to
 be patched up.
 It is best to first set all parameters, perhaps possibly the
 compression type, and then write audio frames using writeframesraw.
 When all frames have been written, either call writeframes(b'') or
 close() to patch up the sizes in the header.
 Marks can be added anytime.  If there are any marks, you must call
 close() after all frames have been written.
 The close() method is called automatically when the class instance
 is destroyed.
 When a file is opened with the extension '.aiff', an AIFF file is
 written, otherwise an AIFF-C file is written.  This default can be
 changed by calling aiff() or aifc() before the first writeframes or
 writeframesraw.
 """
 import struct
 import builtins
 import warnings
 __all__ = ["Error", "open", "openfp"]
 class Error(Exception):
    pass
 _AIFC_version = 0xA2805140     # Version 1 of AIFF-C
 def _read_long(file):
    try:
        return struct.unpack('>l', file.read(4))[0]
    except struct.error:
        raise EOFError from None
 def _read_ulong(file):
    try:
        return struct.unpack('>L', file.read(4))[0]
    except struct.error:
        raise EOFError from None
 def _read_short(file):
    try:
        return struct.unpack('>h', file.read(2))[0]
    except struct.error:
        raise EOFError from None
 def _read_ushort(file):
    try:
        return struct.unpack('>H', file.read(2))[0]
    except struct.error:
        raise EOFError from None
 def _read_string(file):
    length = ord(file.read(1))
    if length == 0:
        data = b''
    else:
        data = file.read(length)
    if length & 1 == 0:
        dummy = file.read(1)
    return data
 _HUGE_VAL = 1.79769313486231e+308 # See <limits.h>
 def _read_float(f): # 10 bytes
    expon = _read_short(f) # 2 bytes
    sign = 1
    if expon < 0:
        sign = -1
        expon = expon + 0x8000
    himant = _read_ulong(f) # 4 bytes
    lomant = _read_ulong(f) # 4 bytes
    if expon == himant == lomant == 0:
        f = 0.0
    elif expon == 0x7FFF:
        f = _HUGE_VAL
    else:
        expon = expon - 16383
        f = (himant * 0x100000000 + lomant) * pow(2.0, expon - 63)
    return sign * f
 def _write_short(f, x):
    f.write(struct.pack('>h', x))
 def _write_ushort(f, x):
    f.write(struct.pack('>H', x))
 def _write_long(f, x):
    f.write(struct.pack('>l', x))
 def _write_ulong(f, x):
    f.write(struct.pack('>L', x))
 def _write_string(f, s):
    if len(s) > 255:
        raise ValueError("string exceeds maximum pstring length")
    f.write(struct.pack('B', len(s)))
    f.write(s)
    if len(s) & 1 == 0:
        f.write(b'\x00')
 def _write_float(f, x):
    import math
    if x < 0:
        sign = 0x8000
        x = x * -1
    else:
        sign = 0
    if x == 0:
        expon = 0
        himant = 0
        lomant = 0
    else:
        fmant, expon = math.frexp(x)
        if expon > 16384 or fmant >= 1 or fmant != fmant: # Infinity or NaN
            expon = sign|0x7FFF
            himant = 0
            lomant = 0
        else:                   # Finite
            expon = expon + 16382
            if expon < 0:           # denormalized
                fmant = math.ldexp(fmant, expon)
                expon = 0
            expon = expon | sign
            fmant = math.ldexp(fmant, 32)
            fsmant = math.floor(fmant)
            himant = int(fsmant)
            fmant = math.ldexp(fmant - fsmant, 32)
            fsmant = math.floor(fmant)
            lomant = int(fsmant)
    _write_ushort(f, expon)
    _write_ulong(f, himant)
    _write_ulong(f, lomant)
 from chunk import Chunk
 from collections import namedtuple
 _aifc_params = namedtuple('_aifc_params',
                          'nchannels sampwidth framerate nframes comptype compname')
 _aifc_params.nchannels.__doc__ = 'Number of audio channels (1 for mono, 2 for stereo)'
 _aifc_params.sampwidth.__doc__ = 'Sample width in bytes'
 _aifc_params.framerate.__doc__ = 'Sampling frequency'
 _aifc_params.nframes.__doc__ = 'Number of audio frames'
 _aifc_params.comptype.__doc__ = 'Compression type ("NONE" for AIFF files)'
 _aifc_params.compname.__doc__ = ("""\
 A human-readable version of the compression type
 ('not compressed' for AIFF files)""")
 class Aifc_read:
    # Variables used in this class:
    #
    # These variables are available to the user though appropriate
    # methods of this class:
    # _file -- the open file with methods read(), close(), and seek()
    #       set through the __init__() method
    # _nchannels -- the number of audio channels
    #       available through the getnchannels() method
    # _nframes -- the number of audio frames
    #       available through the getnframes() method
    # _sampwidth -- the number of bytes per audio sample
    #       available through the getsampwidth() method
    # _framerate -- the sampling frequency
    #       available through the getframerate() method
    # _comptype -- the AIFF-C compression type ('NONE' if AIFF)
    #       available through the getcomptype() method
    # _compname -- the human-readable AIFF-C compression type
    #       available through the getcomptype() method
    # _markers -- the marks in the audio file
    #       available through the getmarkers() and getmark()
    #       methods
    # _soundpos -- the position in the audio stream
    #       available through the tell() method, set through the
    #       setpos() method
    #
    # These variables are used internally only:
    # _version -- the AIFF-C version number
    # _decomp -- the decompressor from builtin module cl
    # _comm_chunk_read -- 1 iff the COMM chunk has been read
    # _aifc -- 1 iff reading an AIFF-C file
    # _ssnd_seek_needed -- 1 iff positioned correctly in audio
    #       file for readframes()
    # _ssnd_chunk -- instantiation of a chunk class for the SSND chunk
    # _framesize -- size of one frame in the file
    _file = None  # Set here since __del__ checks it
    def initfp(self, file):
        self._version = 0
        self._convert = None
        self._markers = []
        self._soundpos = 0
        self._file = file
        chunk = Chunk(file)
        if chunk.getname() != b'FORM':
            raise Error('file does not start with FORM id')
        formdata = chunk.read(4)
        if formdata == b'AIFF':
            self._aifc = 0
        elif formdata == b'AIFC':
            self._aifc = 1
        else:
            raise Error('not an AIFF or AIFF-C file')
        self._comm_chunk_read = 0
        self._ssnd_chunk = None
        while 1:
            self._ssnd_seek_needed = 1
            try:
                chunk = Chunk(self._file)
            except EOFError:
                break
            chunkname = chunk.getname()
            if chunkname == b'COMM':
                self._read_comm_chunk(chunk)
                self._comm_chunk_read = 1
            elif chunkname == b'SSND':
                self._ssnd_chunk = chunk
                dummy = chunk.read(8)
                self._ssnd_seek_needed = 0
            elif chunkname == b'FVER':
                self._version = _read_ulong(chunk)
            elif chunkname == b'MARK':
                self._readmark(chunk)
            chunk.skip()
        if not self._comm_chunk_read or not self._ssnd_chunk:
            raise Error('COMM chunk and/or SSND chunk missing')
    def __init__(self, f):
        if isinstance(f, str):
            file_object = builtins.open(f, 'rb')
            try:
                self.initfp(file_object)
            except:
                file_object.close()
                raise
        else:
            # assume it is an open file object already
            self.initfp(f)
    def __enter__(self):
        return self
    def __exit__(self, *args):
        self.close()
    #
    # User visible methods.
    #
    def getfp(self):
        return self._file
    def rewind(self):
        self._ssnd_seek_needed = 1
        self._soundpos = 0
    def close(self):
        file = self._file
        if file is not None:
            self._file = None
            file.close()
    def tell(self):
        return self._soundpos
    def getnchannels(self):
        return self._nchannels
    def getnframes(self):
        return self._nframes
    def getsampwidth(self):
        return self._sampwidth
    def getframerate(self):
        return self._framerate
    def getcomptype(self):
        return self._comptype
    def getcompname(self):
        return self._compname
 ##  def getversion(self):
 ##      return self._version
    def getparams(self):
        return _aifc_params(self.getnchannels(), self.getsampwidth(),
                            self.getframerate(), self.getnframes(),
                            self.getcomptype(), self.getcompname())
    def getmarkers(self):
        if len(self._markers) == 0:
            return None
        return self._markers
    def getmark(self, id):
        for marker in self._markers:
            if id == marker[0]:
                return marker
        raise Error('marker {0!r} does not exist'.format(id))
    def setpos(self, pos):
        if pos < 0 or pos > self._nframes:
            raise Error('position not in range')
        self._soundpos = pos
        self._ssnd_seek_needed = 1
    def readframes(self, nframes):
        if self._ssnd_seek_needed:
            self._ssnd_chunk.seek(0)
            dummy = self._ssnd_chunk.read(8)
            pos = self._soundpos * self._framesize
            if pos:
                self._ssnd_chunk.seek(pos + 8)
            self._ssnd_seek_needed = 0
        if nframes == 0:
            return b''
        data = self._ssnd_chunk.read(nframes * self._framesize)
        if self._convert and data:
            data = self._convert(data)
        self._soundpos = self._soundpos + len(data) // (self._nchannels
                                                        * self._sampwidth)
        return data
    #
    # Internal methods.
    #
    def _alaw2lin(self, data):
        import audioop
        return audioop.alaw2lin(data, 2)
    def _ulaw2lin(self, data):
        import audioop
        return audioop.ulaw2lin(data, 2)
    def _adpcm2lin(self, data):
        import audioop
        if not hasattr(self, '_adpcmstate'):
            # first time
            self._adpcmstate = None
        data, self._adpcmstate = audioop.adpcm2lin(data, 2, self._adpcmstate)
        return data
    def _read_comm_chunk(self, chunk):
        self._nchannels = _read_short(chunk)
        self._nframes = _read_long(chunk)
        self._sampwidth = (_read_short(chunk) + 7) // 8
        self._framerate = int(_read_float(chunk))
        if self._sampwidth <= 0:
            raise Error('bad sample width')
        if self._nchannels <= 0:
            raise Error('bad # of channels')
        self._framesize = self._nchannels * self._sampwidth
        if self._aifc:
            #DEBUG: SGI's soundeditor produces a bad size :-(
            kludge = 0
            if chunk.chunksize == 18:
                kludge = 1
                warnings.warn('Warning: bad COMM chunk size')
                chunk.chunksize = 23
            #DEBUG end
            self._comptype = chunk.read(4)
            #DEBUG start
            if kludge:
                length = ord(chunk.file.read(1))
                if length & 1 == 0:
                    length = length + 1
                chunk.chunksize = chunk.chunksize + length
                chunk.file.seek(-1, 1)
            #DEBUG end
            self._compname = _read_string(chunk)
            if self._comptype != b'NONE':
                if self._comptype == b'G722':
                    self._convert = self._adpcm2lin
                elif self._comptype in (b'ulaw', b'ULAW'):
                    self._convert = self._ulaw2lin
                elif self._comptype in (b'alaw', b'ALAW'):
                    self._convert = self._alaw2lin
                else:
                    raise Error('unsupported compression type')
                self._sampwidth = 2
        else:
            self._comptype = b'NONE'
            self._compname = b'not compressed'
    def _readmark(self, chunk):
        nmarkers = _read_short(chunk)
        # Some files appear to contain invalid counts.
        # Cope with this by testing for EOF.
        try:
            for i in range(nmarkers):
                id = _read_short(chunk)
                pos = _read_long(chunk)
                name = _read_string(chunk)
                if pos or name:
                    # some files appear to have
                    # dummy markers consisting of
                    # a position 0 and name ''
                    self._markers.append((id, pos, name))
        except EOFError:
            w = ('Warning: MARK chunk contains only %s marker%s instead of %s' %
                 (len(self._markers), '' if len(self._markers) == 1 else 's',
                  nmarkers))
            warnings.warn(w)
 class Aifc_write:
    # Variables used in this class:
    #
    # These variables are user settable through appropriate methods
    # of this class:
    # _file -- the open file with methods write(), close(), tell(), seek()
    #       set through the __init__() method
    # _comptype -- the AIFF-C compression type ('NONE' in AIFF)
    #       set through the setcomptype() or setparams() method
    # _compname -- the human-readable AIFF-C compression type
    #       set through the setcomptype() or setparams() method
    # _nchannels -- the number of audio channels
    #       set through the setnchannels() or setparams() method
    # _sampwidth -- the number of bytes per audio sample
    #       set through the setsampwidth() or setparams() method
    # _framerate -- the sampling frequency
    #       set through the setframerate() or setparams() method
    # _nframes -- the number of audio frames written to the header
    #       set through the setnframes() or setparams() method
    # _aifc -- whether we're writing an AIFF-C file or an AIFF file
    #       set through the aifc() method, reset through the
    #       aiff() method
    #
    # These variables are used internally only:
    # _version -- the AIFF-C version number
    # _comp -- the compressor from builtin module cl
    # _nframeswritten -- the number of audio frames actually written
    # _datalength -- the size of the audio samples written to the header
    # _datawritten -- the size of the audio samples actually written
    _file = None  # Set here since __del__ checks it
    def __init__(self, f):
        if isinstance(f, str):
            file_object = builtins.open(f, 'wb')
            try:
                self.initfp(file_object)
            except:
                file_object.close()
                raise
            # treat .aiff file extensions as non-compressed audio
            if f.endswith('.aiff'):
                self._aifc = 0
        else:
            # assume it is an open file object already
            self.initfp(f)
    def initfp(self, file):
        self._file = file
        self._version = _AIFC_version
        self._comptype = b'NONE'
        self._compname = b'not compressed'
        self._convert = None
        self._nchannels = 0
        self._sampwidth = 0
        self._framerate = 0
        self._nframes = 0
        self._nframeswritten = 0
        self._datawritten = 0
        self._datalength = 0
        self._markers = []
        self._marklength = 0
        self._aifc = 1      # AIFF-C is default
    def __del__(self):
        self.close()
    def __enter__(self):
        return self
    def __exit__(self, *args):
        self.close()
    #
    # User visible methods.
    #
    def aiff(self):
        if self._nframeswritten:
            raise Error('cannot change parameters after starting to write')
        self._aifc = 0
    def aifc(self):
        if self._nframeswritten:
            raise Error('cannot change parameters after starting to write')
        self._aifc = 1
    def setnchannels(self, nchannels):
        if self._nframeswritten:
            raise Error('cannot change parameters after starting to write')
        if nchannels < 1:
            raise Error('bad # of channels')
        self._nchannels = nchannels
    def getnchannels(self):
        if not self._nchannels:
            raise Error('number of channels not set')
        return self._nchannels
    def setsampwidth(self, sampwidth):
        if self._nframeswritten:
            raise Error('cannot change parameters after starting to write')
        if sampwidth < 1 or sampwidth > 4:
            raise Error('bad sample width')
        self._sampwidth = sampwidth
    def getsampwidth(self):
        if not self._sampwidth:
            raise Error('sample width not set')
        return self._sampwidth
    def setframerate(self, framerate):
        if self._nframeswritten:
            raise Error('cannot change parameters after starting to write')
        if framerate <= 0:
            raise Error('bad frame rate')
        self._framerate = framerate
    def getframerate(self):
        if not self._framerate:
            raise Error('frame rate not set')
        return self._framerate
    def setnframes(self, nframes):
        if self._nframeswritten:
            raise Error('cannot change parameters after starting to write')
        self._nframes = nframes
    def getnframes(self):
        return self._nframeswritten
    def setcomptype(self, comptype, compname):
        if self._nframeswritten:
            raise Error('cannot change parameters after starting to write')
        if comptype not in (b'NONE', b'ulaw', b'ULAW',
                            b'alaw', b'ALAW', b'G722'):
            raise Error('unsupported compression type')
        self._comptype = comptype
        self._compname = compname
    def getcomptype(self):
        return self._comptype
    def getcompname(self):
        return self._compname
 ##  def setversion(self, version):
 ##      if self._nframeswritten:
 ##          raise Error, 'cannot change parameters after starting to write'
 ##      self._version = version
    def setparams(self, params):
        nchannels, sampwidth, framerate, nframes, comptype, compname = params
        if self._nframeswritten:
            raise Error('cannot change parameters after starting to write')
        if comptype not in (b'NONE', b'ulaw', b'ULAW',
                            b'alaw', b'ALAW', b'G722'):
            raise Error('unsupported compression type')
        self.setnchannels(nchannels)
        self.setsampwidth(sampwidth)
        self.setframerate(framerate)
        self.setnframes(nframes)
        self.setcomptype(comptype, compname)
    def getparams(self):
        if not self._nchannels or not self._sampwidth or not self._framerate:
            raise Error('not all parameters set')
        return _aifc_params(self._nchannels, self._sampwidth, self._framerate,
                            self._nframes, self._comptype, self._compname)
    def setmark(self, id, pos, name):
        if id <= 0:
            raise Error('marker ID must be > 0')
        if pos < 0:
            raise Error('marker position must be >= 0')
        if not isinstance(name, bytes):
            raise Error('marker name must be bytes')
        for i in range(len(self._markers)):
            if id == self._markers[i][0]:
                self._markers[i] = id, pos, name
                return
        self._markers.append((id, pos, name))
    def getmark(self, id):
        for marker in self._markers:
            if id == marker[0]:
                return marker
        raise Error('marker {0!r} does not exist'.format(id))
    def getmarkers(self):
        if len(self._markers) == 0:
            return None
        return self._markers
    def tell(self):
        return self._nframeswritten
    def writeframesraw(self, data):
        if not isinstance(data, (bytes, bytearray)):
            data = memoryview(data).cast('B')
        self._ensure_header_written(len(data))
        nframes = len(data) // (self._sampwidth * self._nchannels)
        if self._convert:
            data = self._convert(data)
        self._file.write(data)
        self._nframeswritten = self._nframeswritten + nframes
        self._datawritten = self._datawritten + len(data)
    def writeframes(self, data):
        self.writeframesraw(data)
        if self._nframeswritten != self._nframes or \
              self._datalength != self._datawritten:
            self._patchheader()
    def close(self):
        if self._file is None:
            return
        try:
            self._ensure_header_written(0)
            if self._datawritten & 1:
                # quick pad to even size
                self._file.write(b'\x00')
                self._datawritten = self._datawritten + 1
            self._writemarkers()
            if self._nframeswritten != self._nframes or \
                  self._datalength != self._datawritten or \
                  self._marklength:
                self._patchheader()
        finally:
            # Prevent ref cycles
            self._convert = None
            f = self._file
            self._file = None
            f.close()
    #
    # Internal methods.
    #
    def _lin2alaw(self, data):
        import audioop
        return audioop.lin2alaw(data, 2)
    def _lin2ulaw(self, data):
        import audioop
        return audioop.lin2ulaw(data, 2)
    def _lin2adpcm(self, data):
        import audioop
        if not hasattr(self, '_adpcmstate'):
            self._adpcmstate = None
        data, self._adpcmstate = audioop.lin2adpcm(data, 2, self._adpcmstate)
        return data
    def _ensure_header_written(self, datasize):
        if not self._nframeswritten:
            if self._comptype in (b'ULAW', b'ulaw', b'ALAW', b'alaw', b'G722'):
                if not self._sampwidth:
                    self._sampwidth = 2
                if self._sampwidth != 2:
                    raise Error('sample width must be 2 when compressing '
                                'with ulaw/ULAW, alaw/ALAW or G7.22 (ADPCM)')
            if not self._nchannels:
                raise Error('# channels not specified')
            if not self._sampwidth:
                raise Error('sample width not specified')
            if not self._framerate:
                raise Error('sampling rate not specified')
            self._write_header(datasize)
    def _init_compression(self):
        if self._comptype == b'G722':
            self._convert = self._lin2adpcm
        elif self._comptype in (b'ulaw', b'ULAW'):
            self._convert = self._lin2ulaw
        elif self._comptype in (b'alaw', b'ALAW'):
            self._convert = self._lin2alaw
    def _write_header(self, initlength):
        if self._aifc and self._comptype != b'NONE':
            self._init_compression()
        self._file.write(b'FORM')
        if not self._nframes:
            self._nframes = initlength // (self._nchannels * self._sampwidth)
        self._datalength = self._nframes * self._nchannels * self._sampwidth
        if self._datalength & 1:
            self._datalength = self._datalength + 1
        if self._aifc:
            if self._comptype in (b'ulaw', b'ULAW', b'alaw', b'ALAW'):
                self._datalength = self._datalength // 2
                if self._datalength & 1:
                    self._datalength = self._datalength + 1
            elif self._comptype == b'G722':
                self._datalength = (self._datalength + 3) // 4
                if self._datalength & 1:
                    self._datalength = self._datalength + 1
        try:
            self._form_length_pos = self._file.tell()
        except (AttributeError, OSError):
            self._form_length_pos = None
        commlength = self._write_form_length(self._datalength)
        if self._aifc:
            self._file.write(b'AIFC')
            self._file.write(b'FVER')
            _write_ulong(self._file, 4)
            _write_ulong(self._file, self._version)
        else:
            self._file.write(b'AIFF')
        self._file.write(b'COMM')
        _write_ulong(self._file, commlength)
        _write_short(self._file, self._nchannels)
        if self._form_length_pos is not None:
            self._nframes_pos = self._file.tell()
        _write_ulong(self._file, self._nframes)
        if self._comptype in (b'ULAW', b'ulaw', b'ALAW', b'alaw', b'G722'):
            _write_short(self._file, 8)
        else:
            _write_short(self._file, self._sampwidth * 8)
        _write_float(self._file, self._framerate)
        if self._aifc:
            self._file.write(self._comptype)
            _write_string(self._file, self._compname)
        self._file.write(b'SSND')
        if self._form_length_pos is not None:
            self._ssnd_length_pos = self._file.tell()
        _write_ulong(self._file, self._datalength + 8)
        _write_ulong(self._file, 0)
        _write_ulong(self._file, 0)
    def _write_form_length(self, datalength):
        if self._aifc:
            commlength = 18 + 5 + len(self._compname)
            if commlength & 1:
                commlength = commlength + 1
            verslength = 12
        else:
            commlength = 18
            verslength = 0
        _write_ulong(self._file, 4 + verslength + self._marklength + \
                     8 + commlength + 16 + datalength)
        return commlength
    def _patchheader(self):
        curpos = self._file.tell()
        if self._datawritten & 1:
            datalength = self._datawritten + 1
            self._file.write(b'\x00')
        else:
            datalength = self._datawritten
        if datalength == self._datalength and \
              self._nframes == self._nframeswritten and \
              self._marklength == 0:
            self._file.seek(curpos, 0)
            return
        self._file.seek(self._form_length_pos, 0)
        dummy = self._write_form_length(datalength)
        self._file.seek(self._nframes_pos, 0)
        _write_ulong(self._file, self._nframeswritten)
        self._file.seek(self._ssnd_length_pos, 0)
        _write_ulong(self._file, datalength + 8)
        self._file.seek(curpos, 0)
        self._nframes = self._nframeswritten
        self._datalength = datalength
    def _writemarkers(self):
        if len(self._markers) == 0:
            return
        self._file.write(b'MARK')
        length = 2
        for marker in self._markers:
            id, pos, name = marker
            length = length + len(name) + 1 + 6
            if len(name) & 1 == 0:
                length = length + 1
        _write_ulong(self._file, length)
        self._marklength = length + 8
        _write_short(self._file, len(self._markers))
        for marker in self._markers:
            id, pos, name = marker
            _write_short(self._file, id)
            _write_ulong(self._file, pos)
            _write_string(self._file, name)
 def open(f, mode=None):
    if mode is None:
        if hasattr(f, 'mode'):
            mode = f.mode
        else:
            mode = 'rb'
    if mode in ('r', 'rb'):
        return Aifc_read(f)
    elif mode in ('w', 'wb'):
        return Aifc_write(f)
    else:
        raise Error("mode must be 'r', 'rb', 'w', or 'wb'")
 def openfp(f, mode=None):
    warnings.warn("aifc.openfp is deprecated since Python 3.7. "
                  "Use aifc.open instead.", DeprecationWarning, stacklevel=2)
    return open(f, mode=mode)
 if __name__ == '__main__':
    import sys
    if not sys.argv[1:]:
        sys.argv.append('/usr/demos/data/audio/bach.aiff')
    fn = sys.argv[1]
    with open(fn, 'r') as f:
        print("Reading", fn)
        print("nchannels =", f.getnchannels())
        print("nframes   =", f.getnframes())
        print("sampwidth =", f.getsampwidth())
        print("framerate =", f.getframerate())
        print("comptype  =", f.getcomptype())
        print("compname  =", f.getcompname())
        if sys.argv[2:]:
            gn = sys.argv[2]
            print("Writing", gn)
            with open(gn, 'w') as g:
                g.setparams(f.getparams())
                while 1:
                    data = f.readframes(1024)
                    if not data:
                        break
                    g.writeframes(data)
            print("Done.")
--- a/Lib/antigravity.py
+++ b/Lib/antigravity.py
@ -0,0 +1,17 @@
 import webbrowser
 import hashlib
 webbrowser.open("https://xkcd.com/353/")
 def geohash(latitude, longitude, datedow):
    '''Compute geohash() using the Munroe algorithm.
    >>> geohash(37.421542, -122.085589, b'2005-05-26-10458.68')
    37.857713 -122.544543
    '''
    # https://xkcd.com/426/
    h = hashlib.md5(datedow).hexdigest()
    p, q = [('%f' % float.fromhex('0.' + x)) for x in (h[:16], h[16:32])]
    print('%d%s %d%s' % (latitude, p[1:], longitude, q[1:]))
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
--- a/Lib/ast.py
+++ b/Lib/ast.py
@ -0,0 +1,331 @@
 """
    ast
    ~~~
    The `ast` module helps Python applications to process trees of the Python
    abstract syntax grammar.  The abstract syntax itself might change with
    each Python release; this module helps to find out programmatically what
    the current grammar looks like and allows modifications of it.
    An abstract syntax tree can be generated by passing `ast.PyCF_ONLY_AST` as
    a flag to the `compile()` builtin function or by using the `parse()`
    function from this module.  The result will be a tree of objects whose
    classes all inherit from `ast.AST`.
    A modified abstract syntax tree can be compiled into a Python code object
    using the built-in `compile()` function.
    Additionally various helper functions are provided that make working with
    the trees simpler.  The main intention of the helper functions and this
    module in general is to provide an easy to use interface for libraries
    that work tightly with the python syntax (template engines for example).
    :copyright: Copyright 2008 by Armin Ronacher.
    :license: Python License.
 """
 from _ast import *
 def parse(source, filename='<unknown>', mode='exec'):
    """
    Parse the source into an AST node.
    Equivalent to compile(source, filename, mode, PyCF_ONLY_AST).
    """
    return compile(source, filename, mode, PyCF_ONLY_AST)
 def literal_eval(node_or_string):
    """
    Safely evaluate an expression node or a string containing a Python
    expression.  The string or node provided may only consist of the following
    Python literal structures: strings, bytes, numbers, tuples, lists, dicts,
    sets, booleans, and None.
    """
    if isinstance(node_or_string, str):
        node_or_string = parse(node_or_string, mode='eval')
    if isinstance(node_or_string, Expression):
        node_or_string = node_or_string.body
    def _convert_num(node):
        if isinstance(node, Constant):
            if isinstance(node.value, (int, float, complex)):
                return node.value
        elif isinstance(node, Num):
            return node.n
        raise ValueError('malformed node or string: ' + repr(node))
    def _convert_signed_num(node):
        if isinstance(node, UnaryOp) and isinstance(node.op, (UAdd, USub)):
            operand = _convert_num(node.operand)
            if isinstance(node.op, UAdd):
                return + operand
            else:
                return - operand
        return _convert_num(node)
    def _convert(node):
        if isinstance(node, Constant):
            return node.value
        elif isinstance(node, (Str, Bytes)):
            return node.s
        elif isinstance(node, Num):
            return node.n
        elif isinstance(node, Tuple):
            return tuple(map(_convert, node.elts))
        elif isinstance(node, List):
            return list(map(_convert, node.elts))
        elif isinstance(node, Set):
            return set(map(_convert, node.elts))
        elif isinstance(node, Dict):
            return dict(zip(map(_convert, node.keys),
                            map(_convert, node.values)))
        elif isinstance(node, NameConstant):
            return node.value
        elif isinstance(node, BinOp) and isinstance(node.op, (Add, Sub)):
            left = _convert_signed_num(node.left)
            right = _convert_num(node.right)
            if isinstance(left, (int, float)) and isinstance(right, complex):
                if isinstance(node.op, Add):
                    return left + right
                else:
                    return left - right
        return _convert_signed_num(node)
    return _convert(node_or_string)
 def dump(node, annotate_fields=True, include_attributes=False):
    """
    Return a formatted dump of the tree in *node*.  This is mainly useful for
    debugging purposes.  The returned string will show the names and the values
    for fields.  This makes the code impossible to evaluate, so if evaluation is
    wanted *annotate_fields* must be set to False.  Attributes such as line
    numbers and column offsets are not dumped by default.  If this is wanted,
    *include_attributes* can be set to True.
    """
    def _format(node):
        if isinstance(node, AST):
            fields = [(a, _format(b)) for a, b in iter_fields(node)]
            rv = '%s(%s' % (node.__class__.__name__, ', '.join(
                ('%s=%s' % field for field in fields)
                if annotate_fields else
                (b for a, b in fields)
            ))
            if include_attributes and node._attributes:
                rv += fields and ', ' or ' '
                rv += ', '.join('%s=%s' % (a, _format(getattr(node, a)))
                                for a in node._attributes)
            return rv + ')'
        elif isinstance(node, list):
            return '[%s]' % ', '.join(_format(x) for x in node)
        return repr(node)
    if not isinstance(node, AST):
        raise TypeError('expected AST, got %r' % node.__class__.__name__)
    return _format(node)
 def copy_location(new_node, old_node):
    """
    Copy source location (`lineno` and `col_offset` attributes) from
    *old_node* to *new_node* if possible, and return *new_node*.
    """
    for attr in 'lineno', 'col_offset':
        if attr in old_node._attributes and attr in new_node._attributes \
           and hasattr(old_node, attr):
            setattr(new_node, attr, getattr(old_node, attr))
    return new_node
 def fix_missing_locations(node):
    """
    When you compile a node tree with compile(), the compiler expects lineno and
    col_offset attributes for every node that supports them.  This is rather
    tedious to fill in for generated nodes, so this helper adds these attributes
    recursively where not already set, by setting them to the values of the
    parent node.  It works recursively starting at *node*.
    """
    def _fix(node, lineno, col_offset):
        if 'lineno' in node._attributes:
            if not hasattr(node, 'lineno'):
                node.lineno = lineno
            else:
                lineno = node.lineno
        if 'col_offset' in node._attributes:
            if not hasattr(node, 'col_offset'):
                node.col_offset = col_offset
            else:
                col_offset = node.col_offset
        for child in iter_child_nodes(node):
            _fix(child, lineno, col_offset)
    _fix(node, 1, 0)
    return node
 def increment_lineno(node, n=1):
    """
    Increment the line number of each node in the tree starting at *node* by *n*.
    This is useful to "move code" to a different location in a file.
    """
    for child in walk(node):
        if 'lineno' in child._attributes:
            child.lineno = getattr(child, 'lineno', 0) + n
    return node
 def iter_fields(node):
    """
    Yield a tuple of ``(fieldname, value)`` for each field in ``node._fields``
    that is present on *node*.
    """
    for field in node._fields:
        try:
            yield field, getattr(node, field)
        except AttributeError:
            pass
 def iter_child_nodes(node):
    """
    Yield all direct child nodes of *node*, that is, all fields that are nodes
    and all items of fields that are lists of nodes.
    """
    for name, field in iter_fields(node):
        if isinstance(field, AST):
            yield field
        elif isinstance(field, list):
            for item in field:
                if isinstance(item, AST):
                    yield item
 def get_docstring(node, clean=True):
    """
    Return the docstring for the given node or None if no docstring can
    be found.  If the node provided does not have docstrings a TypeError
    will be raised.
    If *clean* is `True`, all tabs are expanded to spaces and any whitespace
    that can be uniformly removed from the second line onwards is removed.
    """
    if not isinstance(node, (AsyncFunctionDef, FunctionDef, ClassDef, Module)):
        raise TypeError("%r can't have docstrings" % node.__class__.__name__)
    if not(node.body and isinstance(node.body[0], Expr)):
        return None
    node = node.body[0].value
    if isinstance(node, Str):
        text = node.s
    elif isinstance(node, Constant) and isinstance(node.value, str):
        text = node.value
    else:
        return None
    if clean:
        import inspect
        text = inspect.cleandoc(text)
    return text
 def walk(node):
    """
    Recursively yield all descendant nodes in the tree starting at *node*
    (including *node* itself), in no specified order.  This is useful if you
    only want to modify nodes in place and don't care about the context.
    """
    from collections import deque
    todo = deque([node])
    while todo:
        node = todo.popleft()
        todo.extend(iter_child_nodes(node))
        yield node
 class NodeVisitor(object):
    """
    A node visitor base class that walks the abstract syntax tree and calls a
    visitor function for every node found.  This function may return a value
    which is forwarded by the `visit` method.
    This class is meant to be subclassed, with the subclass adding visitor
    methods.
    Per default the visitor functions for the nodes are ``'visit_'`` +
    class name of the node.  So a `TryFinally` node visit function would
    be `visit_TryFinally`.  This behavior can be changed by overriding
    the `visit` method.  If no visitor function exists for a node
    (return value `None`) the `generic_visit` visitor is used instead.
    Don't use the `NodeVisitor` if you want to apply changes to nodes during
    traversing.  For this a special visitor exists (`NodeTransformer`) that
    allows modifications.
    """
    def visit(self, node):
        """Visit a node."""
        method = 'visit_' + node.__class__.__name__
        visitor = getattr(self, method, self.generic_visit)
        return visitor(node)
    def generic_visit(self, node):
        """Called if no explicit visitor function exists for a node."""
        for field, value in iter_fields(node):
            if isinstance(value, list):
                for item in value:
                    if isinstance(item, AST):
                        self.visit(item)
            elif isinstance(value, AST):
                self.visit(value)
 class NodeTransformer(NodeVisitor):
    """
    A :class:`NodeVisitor` subclass that walks the abstract syntax tree and
    allows modification of nodes.
    The `NodeTransformer` will walk the AST and use the return value of the
    visitor methods to replace or remove the old node.  If the return value of
    the visitor method is ``None``, the node will be removed from its location,
    otherwise it is replaced with the return value.  The return value may be the
    original node in which case no replacement takes place.
    Here is an example transformer that rewrites all occurrences of name lookups
    (``foo``) to ``data['foo']``::
       class RewriteName(NodeTransformer):
           def visit_Name(self, node):
               return copy_location(Subscript(
                   value=Name(id='data', ctx=Load()),
                   slice=Index(value=Str(s=node.id)),
                   ctx=node.ctx
               ), node)
    Keep in mind that if the node you're operating on has child nodes you must
    either transform the child nodes yourself or call the :meth:`generic_visit`
    method for the node first.
    For nodes that were part of a collection of statements (that applies to all
    statement nodes), the visitor may also return a list of nodes rather than
    just a single node.
    Usually you use the transformer like this::
       node = YourTransformer().visit(node)
    """
    def generic_visit(self, node):
        for field, old_value in iter_fields(node):
            if isinstance(old_value, list):
                new_values = []
                for value in old_value:
                    if isinstance(value, AST):
                        value = self.visit(value)
                        if value is None:
                            continue
                        elif not isinstance(value, AST):
                            new_values.extend(value)
                            continue
                    new_values.append(value)
                old_value[:] = new_values
            elif isinstance(old_value, AST):
                new_node = self.visit(old_value)
                if new_node is None:
                    delattr(node, field)
                else:
                    setattr(node, field, new_node)
        return node
--- a/Lib/asynchat.py
+++ b/Lib/asynchat.py
@ -0,0 +1,307 @@
 # -*- Mode: Python; tab-width: 4 -*-
 #       Id: asynchat.py,v 2.26 2000/09/07 22:29:26 rushing Exp
 #       Author: Sam Rushing <rushing@nightmare.com>
 # ======================================================================
 # Copyright 1996 by Sam Rushing
 #
 #                         All Rights Reserved
 #
 # Permission to use, copy, modify, and distribute this software and
 # its documentation for any purpose and without fee is hereby
 # granted, provided that the above copyright notice appear in all
 # copies and that both that copyright notice and this permission
 # notice appear in supporting documentation, and that the name of Sam
 # Rushing not be used in advertising or publicity pertaining to
 # distribution of the software without specific, written prior
 # permission.
 #
 # SAM RUSHING DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 # INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
 # NO EVENT SHALL SAM RUSHING BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 # CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
 # OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 # NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 # CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 # ======================================================================
 r"""A class supporting chat-style (command/response) protocols.
 This class adds support for 'chat' style protocols - where one side
 sends a 'command', and the other sends a response (examples would be
 the common internet protocols - smtp, nntp, ftp, etc..).
 The handle_read() method looks at the input stream for the current
 'terminator' (usually '\r\n' for single-line responses, '\r\n.\r\n'
 for multi-line output), calling self.found_terminator() on its
 receipt.
 for example:
 Say you build an async nntp client using this class.  At the start
 of the connection, you'll have self.terminator set to '\r\n', in
 order to process the single-line greeting.  Just before issuing a
 'LIST' command you'll set it to '\r\n.\r\n'.  The output of the LIST
 command will be accumulated (using your own 'collect_incoming_data'
 method) up to the terminator, and then control will be returned to
 you - by calling your self.found_terminator() method.
 """
 import asyncore
 from collections import deque
 class async_chat(asyncore.dispatcher):
    """This is an abstract class.  You must derive from this class, and add
    the two methods collect_incoming_data() and found_terminator()"""
    # these are overridable defaults
    ac_in_buffer_size = 65536
    ac_out_buffer_size = 65536
    # we don't want to enable the use of encoding by default, because that is a
    # sign of an application bug that we don't want to pass silently
    use_encoding = 0
    encoding = 'latin-1'
    def __init__(self, sock=None, map=None):
        # for string terminator matching
        self.ac_in_buffer = b''
        # we use a list here rather than io.BytesIO for a few reasons...
        # del lst[:] is faster than bio.truncate(0)
        # lst = [] is faster than bio.truncate(0)
        self.incoming = []
        # we toss the use of the "simple producer" and replace it with
        # a pure deque, which the original fifo was a wrapping of
        self.producer_fifo = deque()
        asyncore.dispatcher.__init__(self, sock, map)
    def collect_incoming_data(self, data):
        raise NotImplementedError("must be implemented in subclass")
    def _collect_incoming_data(self, data):
        self.incoming.append(data)
    def _get_data(self):
        d = b''.join(self.incoming)
        del self.incoming[:]
        return d
    def found_terminator(self):
        raise NotImplementedError("must be implemented in subclass")
    def set_terminator(self, term):
        """Set the input delimiter.
        Can be a fixed string of any length, an integer, or None.
        """
        if isinstance(term, str) and self.use_encoding:
            term = bytes(term, self.encoding)
        elif isinstance(term, int) and term < 0:
            raise ValueError('the number of received bytes must be positive')
        self.terminator = term
    def get_terminator(self):
        return self.terminator
    # grab some more data from the socket,
    # throw it to the collector method,
    # check for the terminator,
    # if found, transition to the next state.
    def handle_read(self):
        try:
            data = self.recv(self.ac_in_buffer_size)
        except BlockingIOError:
            return
        except OSError as why:
            self.handle_error()
            return
        if isinstance(data, str) and self.use_encoding:
            data = bytes(str, self.encoding)
        self.ac_in_buffer = self.ac_in_buffer + data
        # Continue to search for self.terminator in self.ac_in_buffer,
        # while calling self.collect_incoming_data.  The while loop
        # is necessary because we might read several data+terminator
        # combos with a single recv(4096).
        while self.ac_in_buffer:
            lb = len(self.ac_in_buffer)
            terminator = self.get_terminator()
            if not terminator:
                # no terminator, collect it all
                self.collect_incoming_data(self.ac_in_buffer)
                self.ac_in_buffer = b''
            elif isinstance(terminator, int):
                # numeric terminator
                n = terminator
                if lb < n:
                    self.collect_incoming_data(self.ac_in_buffer)
                    self.ac_in_buffer = b''
                    self.terminator = self.terminator - lb
                else:
                    self.collect_incoming_data(self.ac_in_buffer[:n])
                    self.ac_in_buffer = self.ac_in_buffer[n:]
                    self.terminator = 0
                    self.found_terminator()
            else:
                # 3 cases:
                # 1) end of buffer matches terminator exactly:
                #    collect data, transition
                # 2) end of buffer matches some prefix:
                #    collect data to the prefix
                # 3) end of buffer does not match any prefix:
                #    collect data
                terminator_len = len(terminator)
                index = self.ac_in_buffer.find(terminator)
                if index != -1:
                    # we found the terminator
                    if index > 0:
                        # don't bother reporting the empty string
                        # (source of subtle bugs)
                        self.collect_incoming_data(self.ac_in_buffer[:index])
                    self.ac_in_buffer = self.ac_in_buffer[index+terminator_len:]
                    # This does the Right Thing if the terminator
                    # is changed here.
                    self.found_terminator()
                else:
                    # check for a prefix of the terminator
                    index = find_prefix_at_end(self.ac_in_buffer, terminator)
                    if index:
                        if index != lb:
                            # we found a prefix, collect up to the prefix
                            self.collect_incoming_data(self.ac_in_buffer[:-index])
                            self.ac_in_buffer = self.ac_in_buffer[-index:]
                        break
                    else:
                        # no prefix, collect it all
                        self.collect_incoming_data(self.ac_in_buffer)
                        self.ac_in_buffer = b''
    def handle_write(self):
        self.initiate_send()
    def handle_close(self):
        self.close()
    def push(self, data):
        if not isinstance(data, (bytes, bytearray, memoryview)):
            raise TypeError('data argument must be byte-ish (%r)',
                            type(data))
        sabs = self.ac_out_buffer_size
        if len(data) > sabs:
            for i in range(0, len(data), sabs):
                self.producer_fifo.append(data[i:i+sabs])
        else:
            self.producer_fifo.append(data)
        self.initiate_send()
    def push_with_producer(self, producer):
        self.producer_fifo.append(producer)
        self.initiate_send()
    def readable(self):
        "predicate for inclusion in the readable for select()"
        # cannot use the old predicate, it violates the claim of the
        # set_terminator method.
        # return (len(self.ac_in_buffer) <= self.ac_in_buffer_size)
        return 1
    def writable(self):
        "predicate for inclusion in the writable for select()"
        return self.producer_fifo or (not self.connected)
    def close_when_done(self):
        "automatically close this channel once the outgoing queue is empty"
        self.producer_fifo.append(None)
    def initiate_send(self):
        while self.producer_fifo and self.connected:
            first = self.producer_fifo[0]
            # handle empty string/buffer or None entry
            if not first:
                del self.producer_fifo[0]
                if first is None:
                    self.handle_close()
                    return
            # handle classic producer behavior
            obs = self.ac_out_buffer_size
            try:
                data = first[:obs]
            except TypeError:
                data = first.more()
                if data:
                    self.producer_fifo.appendleft(data)
                else:
                    del self.producer_fifo[0]
                continue
            if isinstance(data, str) and self.use_encoding:
                data = bytes(data, self.encoding)
            # send the data
            try:
                num_sent = self.send(data)
            except OSError:
                self.handle_error()
                return
            if num_sent:
                if num_sent < len(data) or obs < len(first):
                    self.producer_fifo[0] = first[num_sent:]
                else:
                    del self.producer_fifo[0]
            # we tried to send some actual data
            return
    def discard_buffers(self):
        # Emergencies only!
        self.ac_in_buffer = b''
        del self.incoming[:]
        self.producer_fifo.clear()
 class simple_producer:
    def __init__(self, data, buffer_size=512):
        self.data = data
        self.buffer_size = buffer_size
    def more(self):
        if len(self.data) > self.buffer_size:
            result = self.data[:self.buffer_size]
            self.data = self.data[self.buffer_size:]
            return result
        else:
            result = self.data
            self.data = b''
            return result
 # Given 'haystack', see if any prefix of 'needle' is at its end.  This
 # assumes an exact match has already been checked.  Return the number of
 # characters matched.
 # for example:
 # f_p_a_e("qwerty\r", "\r\n") => 1
 # f_p_a_e("qwertydkjf", "\r\n") => 0
 # f_p_a_e("qwerty\r\n", "\r\n") => <undefined>
 # this could maybe be made faster with a computed regex?
 # [answer: no; circa Python-2.0, Jan 2001]
 # new python:   28961/s
 # old python:   18307/s
 # re:        12820/s
 # regex:     14035/s
 def find_prefix_at_end(haystack, needle):
    l = len(needle) - 1
    while l and not haystack.endswith(needle[:l]):
        l -= 1
    return l
--- a/Lib/asyncio/init.py
+++ b/Lib/asyncio/init.py
@ -0,0 +1,43 @@
 """The asyncio package, tracking PEP 3156."""
 # flake8: noqa
 import sys
 # This relies on each of the submodules having an __all__ variable.
 from .base_events import *
 from .coroutines import *
 from .events import *
 from .futures import *
 from .locks import *
 from .protocols import *
 from .runners import *
 from .queues import *
 from .streams import *
 from .subprocess import *
 from .tasks import *
 from .transports import *
 # Exposed for _asynciomodule.c to implement now deprecated
 # Task.all_tasks() method.  This function will be removed in 3.9.
 from .tasks import _all_tasks_compat  # NoQA
 __all__ = (base_events.__all__ +
           coroutines.__all__ +
           events.__all__ +
           futures.__all__ +
           locks.__all__ +
           protocols.__all__ +
           runners.__all__ +
           queues.__all__ +
           streams.__all__ +
           subprocess.__all__ +
           tasks.__all__ +
           transports.__all__)
 if sys.platform == 'win32':  # pragma: no cover
    from .windows_events import *
    __all__ += windows_events.__all__
 else:
    from .unix_events import *  # pragma: no cover
    __all__ += unix_events.__all__
--- a/Lib/asyncio/base_events.py
+++ b/Lib/asyncio/base_events.py
--- a/Lib/asyncio/base_futures.py
+++ b/Lib/asyncio/base_futures.py
@ -0,0 +1,71 @@
 __all__ = ()
 import concurrent.futures._base
 import reprlib
 from . import format_helpers
 Error = concurrent.futures._base.Error
 CancelledError = concurrent.futures.CancelledError
 TimeoutError = concurrent.futures.TimeoutError
 class InvalidStateError(Error):
    """The operation is not allowed in this state."""
 # States for Future.
 _PENDING = 'PENDING'
 _CANCELLED = 'CANCELLED'
 _FINISHED = 'FINISHED'
 def isfuture(obj):
    """Check for a Future.
    This returns True when obj is a Future instance or is advertising
    itself as duck-type compatible by setting _asyncio_future_blocking.
    See comment in Future for more details.
    """
    return (hasattr(obj.__class__, '_asyncio_future_blocking') and
            obj._asyncio_future_blocking is not None)
 def _format_callbacks(cb):
    """helper function for Future.__repr__"""
    size = len(cb)
    if not size:
        cb = ''
    def format_cb(callback):
        return format_helpers._format_callback_source(callback, ())
    if size == 1:
        cb = format_cb(cb[0][0])
    elif size == 2:
        cb = '{}, {}'.format(format_cb(cb[0][0]), format_cb(cb[1][0]))
    elif size > 2:
        cb = '{}, <{} more>, {}'.format(format_cb(cb[0][0]),
                                        size - 2,
                                        format_cb(cb[-1][0]))
    return f'cb=[{cb}]'
 def _future_repr_info(future):
    # (Future) -> str
    """helper function for Future.__repr__"""
    info = [future._state.lower()]
    if future._state == _FINISHED:
        if future._exception is not None:
            info.append(f'exception={future._exception!r}')
        else:
            # use reprlib to limit the length of the output, especially
            # for very long strings
            result = reprlib.repr(future._result)
            info.append(f'result={result}')
    if future._callbacks:
        info.append(_format_callbacks(future._callbacks))
    if future._source_traceback:
        frame = future._source_traceback[-1]
        info.append(f'created at {frame[0]}:{frame[1]}')
    return info
--- a/Lib/asyncio/base_subprocess.py
+++ b/Lib/asyncio/base_subprocess.py
@ -0,0 +1,284 @@
 import collections
 import subprocess
 import warnings
 from . import protocols
 from . import transports
 from .log import logger
 class BaseSubprocessTransport(transports.SubprocessTransport):
    def __init__(self, loop, protocol, args, shell,
                 stdin, stdout, stderr, bufsize,
                 waiter=None, extra=None, **kwargs):
        super().__init__(extra)
        self._closed = False
        self._protocol = protocol
        self._loop = loop
        self._proc = None
        self._pid = None
        self._returncode = None
        self._exit_waiters = []
        self._pending_calls = collections.deque()
        self._pipes = {}
        self._finished = False
        if stdin == subprocess.PIPE:
            self._pipes[0] = None
        if stdout == subprocess.PIPE:
            self._pipes[1] = None
        if stderr == subprocess.PIPE:
            self._pipes[2] = None
        # Create the child process: set the _proc attribute
        try:
            self._start(args=args, shell=shell, stdin=stdin, stdout=stdout,
                        stderr=stderr, bufsize=bufsize, **kwargs)
        except:
            self.close()
            raise
        self._pid = self._proc.pid
        self._extra['subprocess'] = self._proc
        if self._loop.get_debug():
            if isinstance(args, (bytes, str)):
                program = args
            else:
                program = args[0]
            logger.debug('process %r created: pid %s',
                         program, self._pid)
        self._loop.create_task(self._connect_pipes(waiter))
    def __repr__(self):
        info = [self.__class__.__name__]
        if self._closed:
            info.append('closed')
        if self._pid is not None:
            info.append(f'pid={self._pid}')
        if self._returncode is not None:
            info.append(f'returncode={self._returncode}')
        elif self._pid is not None:
            info.append('running')
        else:
            info.append('not started')
        stdin = self._pipes.get(0)
        if stdin is not None:
            info.append(f'stdin={stdin.pipe}')
        stdout = self._pipes.get(1)
        stderr = self._pipes.get(2)
        if stdout is not None and stderr is stdout:
            info.append(f'stdout=stderr={stdout.pipe}')
        else:
            if stdout is not None:
                info.append(f'stdout={stdout.pipe}')
            if stderr is not None:
                info.append(f'stderr={stderr.pipe}')
        return '<{}>'.format(' '.join(info))
    def _start(self, args, shell, stdin, stdout, stderr, bufsize, **kwargs):
        raise NotImplementedError
    def set_protocol(self, protocol):
        self._protocol = protocol
    def get_protocol(self):
        return self._protocol
    def is_closing(self):
        return self._closed
    def close(self):
        if self._closed:
            return
        self._closed = True
        for proto in self._pipes.values():
            if proto is None:
                continue
            proto.pipe.close()
        if (self._proc is not None and
                # has the child process finished?
                self._returncode is None and
                # the child process has finished, but the
                # transport hasn't been notified yet?
                self._proc.poll() is None):
            if self._loop.get_debug():
                logger.warning('Close running child process: kill %r', self)
            try:
                self._proc.kill()
            except ProcessLookupError:
                pass
            # Don't clear the _proc reference yet: _post_init() may still run
    def __del__(self):
        if not self._closed:
            warnings.warn(f"unclosed transport {self!r}", ResourceWarning,
                          source=self)
            self.close()
    def get_pid(self):
        return self._pid
    def get_returncode(self):
        return self._returncode
    def get_pipe_transport(self, fd):
        if fd in self._pipes:
            return self._pipes[fd].pipe
        else:
            return None
    def _check_proc(self):
        if self._proc is None:
            raise ProcessLookupError()
    def send_signal(self, signal):
        self._check_proc()
        self._proc.send_signal(signal)
    def terminate(self):
        self._check_proc()
        self._proc.terminate()
    def kill(self):
        self._check_proc()
        self._proc.kill()
    async def _connect_pipes(self, waiter):
        try:
            proc = self._proc
            loop = self._loop
            if proc.stdin is not None:
                _, pipe = await loop.connect_write_pipe(
                    lambda: WriteSubprocessPipeProto(self, 0),
                    proc.stdin)
                self._pipes[0] = pipe
            if proc.stdout is not None:
                _, pipe = await loop.connect_read_pipe(
                    lambda: ReadSubprocessPipeProto(self, 1),
                    proc.stdout)
                self._pipes[1] = pipe
            if proc.stderr is not None:
                _, pipe = await loop.connect_read_pipe(
                    lambda: ReadSubprocessPipeProto(self, 2),
                    proc.stderr)
                self._pipes[2] = pipe
            assert self._pending_calls is not None
            loop.call_soon(self._protocol.connection_made, self)
            for callback, data in self._pending_calls:
                loop.call_soon(callback, *data)
            self._pending_calls = None
        except Exception as exc:
            if waiter is not None and not waiter.cancelled():
                waiter.set_exception(exc)
        else:
            if waiter is not None and not waiter.cancelled():
                waiter.set_result(None)
    def _call(self, cb, *data):
        if self._pending_calls is not None:
            self._pending_calls.append((cb, data))
        else:
            self._loop.call_soon(cb, *data)
    def _pipe_connection_lost(self, fd, exc):
        self._call(self._protocol.pipe_connection_lost, fd, exc)
        self._try_finish()
    def _pipe_data_received(self, fd, data):
        self._call(self._protocol.pipe_data_received, fd, data)
    def _process_exited(self, returncode):
        assert returncode is not None, returncode
        assert self._returncode is None, self._returncode
        if self._loop.get_debug():
            logger.info('%r exited with return code %r', self, returncode)
        self._returncode = returncode
        if self._proc.returncode is None:
            # asyncio uses a child watcher: copy the status into the Popen
            # object. On Python 3.6, it is required to avoid a ResourceWarning.
            self._proc.returncode = returncode
        self._call(self._protocol.process_exited)
        self._try_finish()
        # wake up futures waiting for wait()
        for waiter in self._exit_waiters:
            if not waiter.cancelled():
                waiter.set_result(returncode)
        self._exit_waiters = None
    async def _wait(self):
        """Wait until the process exit and return the process return code.
        This method is a coroutine."""
        if self._returncode is not None:
            return self._returncode
        waiter = self._loop.create_future()
        self._exit_waiters.append(waiter)
        return await waiter
    def _try_finish(self):
        assert not self._finished
        if self._returncode is None:
            return
        if all(p is not None and p.disconnected
               for p in self._pipes.values()):
            self._finished = True
            self._call(self._call_connection_lost, None)
    def _call_connection_lost(self, exc):
        try:
            self._protocol.connection_lost(exc)
        finally:
            self._loop = None
            self._proc = None
            self._protocol = None
 class WriteSubprocessPipeProto(protocols.BaseProtocol):
    def __init__(self, proc, fd):
        self.proc = proc
        self.fd = fd
        self.pipe = None
        self.disconnected = False
    def connection_made(self, transport):
        self.pipe = transport
    def __repr__(self):
        return f'<{self.__class__.__name__} fd={self.fd} pipe={self.pipe!r}>'
    def connection_lost(self, exc):
        self.disconnected = True
        self.proc._pipe_connection_lost(self.fd, exc)
        self.proc = None
    def pause_writing(self):
        self.proc._protocol.pause_writing()
    def resume_writing(self):
        self.proc._protocol.resume_writing()
 class ReadSubprocessPipeProto(WriteSubprocessPipeProto,
                              protocols.Protocol):
    def data_received(self, data):
        self.proc._pipe_data_received(self.fd, data)
--- a/Lib/asyncio/base_tasks.py
+++ b/Lib/asyncio/base_tasks.py
@ -0,0 +1,76 @@
 import linecache
 import traceback
 from . import base_futures
 from . import coroutines
 def _task_repr_info(task):
    info = base_futures._future_repr_info(task)
    if task._must_cancel:
        # replace status
        info[0] = 'cancelling'
    coro = coroutines._format_coroutine(task._coro)
    info.insert(1, f'coro=<{coro}>')
    if task._fut_waiter is not None:
        info.insert(2, f'wait_for={task._fut_waiter!r}')
    return info
 def _task_get_stack(task, limit):
    frames = []
    try:
        # 'async def' coroutines
        f = task._coro.cr_frame
    except AttributeError:
        f = task._coro.gi_frame
    if f is not None:
        while f is not None:
            if limit is not None:
                if limit <= 0:
                    break
                limit -= 1
            frames.append(f)
            f = f.f_back
        frames.reverse()
    elif task._exception is not None:
        tb = task._exception.__traceback__
        while tb is not None:
            if limit is not None:
                if limit <= 0:
                    break
                limit -= 1
            frames.append(tb.tb_frame)
            tb = tb.tb_next
    return frames
 def _task_print_stack(task, limit, file):
    extracted_list = []
    checked = set()
    for f in task.get_stack(limit=limit):
        lineno = f.f_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        if filename not in checked:
            checked.add(filename)
            linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        extracted_list.append((filename, lineno, name, line))
    exc = task._exception
    if not extracted_list:
        print(f'No stack for {task!r}', file=file)
    elif exc is not None:
        print(f'Traceback for {task!r} (most recent call last):', file=file)
    else:
        print(f'Stack for {task!r} (most recent call last):', file=file)
    traceback.print_list(extracted_list, file=file)
    if exc is not None:
        for line in traceback.format_exception_only(exc.__class__, exc):
            print(line, file=file, end='')
--- a/Lib/asyncio/constants.py
+++ b/Lib/asyncio/constants.py
@ -0,0 +1,27 @@
 import enum
 # After the connection is lost, log warnings after this many write()s.
 LOG_THRESHOLD_FOR_CONNLOST_WRITES = 5
 # Seconds to wait before retrying accept().
 ACCEPT_RETRY_DELAY = 1
 # Number of stack entries to capture in debug mode.
 # The larger the number, the slower the operation in debug mode
 # (see extract_stack() in format_helpers.py).
 DEBUG_STACK_DEPTH = 10
 # Number of seconds to wait for SSL handshake to complete
 # The default timeout matches that of Nginx.
 SSL_HANDSHAKE_TIMEOUT = 60.0
 # Used in sendfile fallback code.  We use fallback for platforms
 # that don't support sendfile, or for TLS connections.
 SENDFILE_FALLBACK_READBUFFER_SIZE = 1024 * 256
 # The enum should be here to break circular dependencies between
 # base_events and sslproto
 class _SendfileMode(enum.Enum):
    UNSUPPORTED = enum.auto()
    TRY_NATIVE = enum.auto()
    FALLBACK = enum.auto()
--- a/Lib/asyncio/coroutines.py
+++ b/Lib/asyncio/coroutines.py
@ -0,0 +1,265 @@
 __all__ = 'coroutine', 'iscoroutinefunction', 'iscoroutine'
 import collections.abc
 import functools
 import inspect
 import os
 import sys
 import traceback
 import types
 from . import base_futures
 from . import constants
 from . import format_helpers
 from .log import logger
 def _is_debug_mode():
    # If you set _DEBUG to true, @coroutine will wrap the resulting
    # generator objects in a CoroWrapper instance (defined below).  That
    # instance will log a message when the generator is never iterated
    # over, which may happen when you forget to use "await" or "yield from"
    # with a coroutine call.
    # Note that the value of the _DEBUG flag is taken
    # when the decorator is used, so to be of any use it must be set
    # before you define your coroutines.  A downside of using this feature
    # is that tracebacks show entries for the CoroWrapper.__next__ method
    # when _DEBUG is true.
    return sys.flags.dev_mode or (not sys.flags.ignore_environment and
                                  bool(os.environ.get('PYTHONASYNCIODEBUG')))
 _DEBUG = _is_debug_mode()
 class CoroWrapper:
    # Wrapper for coroutine object in _DEBUG mode.
    def __init__(self, gen, func=None):
        assert inspect.isgenerator(gen) or inspect.iscoroutine(gen), gen
        self.gen = gen
        self.func = func  # Used to unwrap @coroutine decorator
        self._source_traceback = format_helpers.extract_stack(sys._getframe(1))
        self.__name__ = getattr(gen, '__name__', None)
        self.__qualname__ = getattr(gen, '__qualname__', None)
    def __repr__(self):
        coro_repr = _format_coroutine(self)
        if self._source_traceback:
            frame = self._source_traceback[-1]
            coro_repr += f', created at {frame[0]}:{frame[1]}'
        return f'<{self.__class__.__name__} {coro_repr}>'
    def __iter__(self):
        return self
    def __next__(self):
        return self.gen.send(None)
    def send(self, value):
        return self.gen.send(value)
    def throw(self, type, value=None, traceback=None):
        return self.gen.throw(type, value, traceback)
    def close(self):
        return self.gen.close()
    @property
    def gi_frame(self):
        return self.gen.gi_frame
    @property
    def gi_running(self):
        return self.gen.gi_running
    @property
    def gi_code(self):
        return self.gen.gi_code
    def __await__(self):
        return self
    @property
    def gi_yieldfrom(self):
        return self.gen.gi_yieldfrom
    def __del__(self):
        # Be careful accessing self.gen.frame -- self.gen might not exist.
        gen = getattr(self, 'gen', None)
        frame = getattr(gen, 'gi_frame', None)
        if frame is not None and frame.f_lasti == -1:
            msg = f'{self!r} was never yielded from'
            tb = getattr(self, '_source_traceback', ())
            if tb:
                tb = ''.join(traceback.format_list(tb))
                msg += (f'\nCoroutine object created at '
                        f'(most recent call last, truncated to '
                        f'{constants.DEBUG_STACK_DEPTH} last lines):\n')
                msg += tb.rstrip()
            logger.error(msg)
 def coroutine(func):
    """Decorator to mark coroutines.
    If the coroutine is not yielded from before it is destroyed,
    an error message is logged.
    """
    if inspect.iscoroutinefunction(func):
        # In Python 3.5 that's all we need to do for coroutines
        # defined with "async def".
        return func
    if inspect.isgeneratorfunction(func):
        coro = func
    else:
        @functools.wraps(func)
        def coro(*args, **kw):
            res = func(*args, **kw)
            if (base_futures.isfuture(res) or inspect.isgenerator(res) or
                    isinstance(res, CoroWrapper)):
                res = yield from res
            else:
                # If 'res' is an awaitable, run it.
                try:
                    await_meth = res.__await__
                except AttributeError:
                    pass
                else:
                    if isinstance(res, collections.abc.Awaitable):
                        res = yield from await_meth()
            return res
    coro = types.coroutine(coro)
    if not _DEBUG:
        wrapper = coro
    else:
        @functools.wraps(func)
        def wrapper(*args, **kwds):
            w = CoroWrapper(coro(*args, **kwds), func=func)
            if w._source_traceback:
                del w._source_traceback[-1]
            # Python < 3.5 does not implement __qualname__
            # on generator objects, so we set it manually.
            # We use getattr as some callables (such as
            # functools.partial may lack __qualname__).
            w.__name__ = getattr(func, '__name__', None)
            w.__qualname__ = getattr(func, '__qualname__', None)
            return w
    wrapper._is_coroutine = _is_coroutine  # For iscoroutinefunction().
    return wrapper
 # A marker for iscoroutinefunction.
 _is_coroutine = object()
 def iscoroutinefunction(func):
    """Return True if func is a decorated coroutine function."""
    return (inspect.iscoroutinefunction(func) or
            getattr(func, '_is_coroutine', None) is _is_coroutine)
 # Prioritize native coroutine check to speed-up
 # asyncio.iscoroutine.
 _COROUTINE_TYPES = (types.CoroutineType, types.GeneratorType,
                    collections.abc.Coroutine, CoroWrapper)
 _iscoroutine_typecache = set()
 def iscoroutine(obj):
    """Return True if obj is a coroutine object."""
    if type(obj) in _iscoroutine_typecache:
        return True
    if isinstance(obj, _COROUTINE_TYPES):
        # Just in case we don't want to cache more than 100
        # positive types.  That shouldn't ever happen, unless
        # someone stressing the system on purpose.
        if len(_iscoroutine_typecache) < 100:
            _iscoroutine_typecache.add(type(obj))
        return True
    else:
        return False
 def _format_coroutine(coro):
    assert iscoroutine(coro)
    is_corowrapper = isinstance(coro, CoroWrapper)
    def get_name(coro):
        # Coroutines compiled with Cython sometimes don't have
        # proper __qualname__ or __name__.  While that is a bug
        # in Cython, asyncio shouldn't crash with an AttributeError
        # in its __repr__ functions.
        if is_corowrapper:
            return format_helpers._format_callback(coro.func, (), {})
        if hasattr(coro, '__qualname__') and coro.__qualname__:
            coro_name = coro.__qualname__
        elif hasattr(coro, '__name__') and coro.__name__:
            coro_name = coro.__name__
        else:
            # Stop masking Cython bugs, expose them in a friendly way.
            coro_name = f'<{type(coro).__name__} without __name__>'
        return f'{coro_name}()'
    def is_running(coro):
        try:
            return coro.cr_running
        except AttributeError:
            try:
                return coro.gi_running
            except AttributeError:
                return False
    coro_code = None
    if hasattr(coro, 'cr_code') and coro.cr_code:
        coro_code = coro.cr_code
    elif hasattr(coro, 'gi_code') and coro.gi_code:
        coro_code = coro.gi_code
    coro_name = get_name(coro)
    if not coro_code:
        # Built-in types might not have __qualname__ or __name__.
        if is_running(coro):
            return f'{coro_name} running'
        else:
            return coro_name
    coro_frame = None
    if hasattr(coro, 'gi_frame') and coro.gi_frame:
        coro_frame = coro.gi_frame
    elif hasattr(coro, 'cr_frame') and coro.cr_frame:
        coro_frame = coro.cr_frame
    # If Cython's coroutine has a fake code object without proper
    # co_filename -- expose that.
    filename = coro_code.co_filename or '<empty co_filename>'
    lineno = 0
    if (is_corowrapper and
            coro.func is not None and
            not inspect.isgeneratorfunction(coro.func)):
        source = format_helpers._get_function_source(coro.func)
        if source is not None:
            filename, lineno = source
        if coro_frame is None:
            coro_repr = f'{coro_name} done, defined at {filename}:{lineno}'
        else:
            coro_repr = f'{coro_name} running, defined at {filename}:{lineno}'
    elif coro_frame is not None:
        lineno = coro_frame.f_lineno
        coro_repr = f'{coro_name} running at {filename}:{lineno}'
    else:
        lineno = coro_code.co_firstlineno
        coro_repr = f'{coro_name} done, defined at {filename}:{lineno}'
    return coro_repr
--- a/Lib/asyncio/events.py
+++ b/Lib/asyncio/events.py
@ -0,0 +1,796 @@
 """Event loop and event loop policy."""
 __all__ = (
    'AbstractEventLoopPolicy',
    'AbstractEventLoop', 'AbstractServer',
    'Handle', 'TimerHandle', 'SendfileNotAvailableError',
    'get_event_loop_policy', 'set_event_loop_policy',
    'get_event_loop', 'set_event_loop', 'new_event_loop',
    'get_child_watcher', 'set_child_watcher',
    '_set_running_loop', 'get_running_loop',
    '_get_running_loop',
 )
 import contextvars
 import os
 import socket
 import subprocess
 import sys
 import threading
 from . import format_helpers
 class SendfileNotAvailableError(RuntimeError):
    """Sendfile syscall is not available.
    Raised if OS does not support sendfile syscall for given socket or
    file type.
    """
 class Handle:
    """Object returned by callback registration methods."""
    __slots__ = ('_callback', '_args', '_cancelled', '_loop',
                 '_source_traceback', '_repr', '__weakref__',
                 '_context')
    def __init__(self, callback, args, loop, context=None):
        if context is None:
            context = contextvars.copy_context()
        self._context = context
        self._loop = loop
        self._callback = callback
        self._args = args
        self._cancelled = False
        self._repr = None
        if self._loop.get_debug():
            self._source_traceback = format_helpers.extract_stack(
                sys._getframe(1))
        else:
            self._source_traceback = None
    def _repr_info(self):
        info = [self.__class__.__name__]
        if self._cancelled:
            info.append('cancelled')
        if self._callback is not None:
            info.append(format_helpers._format_callback_source(
                self._callback, self._args))
        if self._source_traceback:
            frame = self._source_traceback[-1]
            info.append(f'created at {frame[0]}:{frame[1]}')
        return info
    def __repr__(self):
        if self._repr is not None:
            return self._repr
        info = self._repr_info()
        return '<{}>'.format(' '.join(info))
    def cancel(self):
        if not self._cancelled:
            self._cancelled = True
            if self._loop.get_debug():
                # Keep a representation in debug mode to keep callback and
                # parameters. For example, to log the warning
                # "Executing <Handle...> took 2.5 second"
                self._repr = repr(self)
            self._callback = None
            self._args = None
    def cancelled(self):
        return self._cancelled
    def _run(self):
        try:
            self._context.run(self._callback, *self._args)
        except Exception as exc:
            cb = format_helpers._format_callback_source(
                self._callback, self._args)
            msg = f'Exception in callback {cb}'
            context = {
                'message': msg,
                'exception': exc,
                'handle': self,
            }
            if self._source_traceback:
                context['source_traceback'] = self._source_traceback
            self._loop.call_exception_handler(context)
        self = None  # Needed to break cycles when an exception occurs.
 class TimerHandle(Handle):
    """Object returned by timed callback registration methods."""
    __slots__ = ['_scheduled', '_when']
    def __init__(self, when, callback, args, loop, context=None):
        assert when is not None
        super().__init__(callback, args, loop, context)
        if self._source_traceback:
            del self._source_traceback[-1]
        self._when = when
        self._scheduled = False
    def _repr_info(self):
        info = super()._repr_info()
        pos = 2 if self._cancelled else 1
        info.insert(pos, f'when={self._when}')
        return info
    def __hash__(self):
        return hash(self._when)
    def __lt__(self, other):
        return self._when < other._when
    def __le__(self, other):
        if self._when < other._when:
            return True
        return self.__eq__(other)
    def __gt__(self, other):
        return self._when > other._when
    def __ge__(self, other):
        if self._when > other._when:
            return True
        return self.__eq__(other)
    def __eq__(self, other):
        if isinstance(other, TimerHandle):
            return (self._when == other._when and
                    self._callback == other._callback and
                    self._args == other._args and
                    self._cancelled == other._cancelled)
        return NotImplemented
    def __ne__(self, other):
        equal = self.__eq__(other)
        return NotImplemented if equal is NotImplemented else not equal
    def cancel(self):
        if not self._cancelled:
            self._loop._timer_handle_cancelled(self)
        super().cancel()
    def when(self):
        """Return a scheduled callback time.
        The time is an absolute timestamp, using the same time
        reference as loop.time().
        """
        return self._when
 class AbstractServer:
    """Abstract server returned by create_server()."""
    def close(self):
        """Stop serving.  This leaves existing connections open."""
        raise NotImplementedError
    def get_loop(self):
        """Get the event loop the Server object is attached to."""
        raise NotImplementedError
    def is_serving(self):
        """Return True if the server is accepting connections."""
        raise NotImplementedError
    async def start_serving(self):
        """Start accepting connections.
        This method is idempotent, so it can be called when
        the server is already being serving.
        """
        raise NotImplementedError
    async def serve_forever(self):
        """Start accepting connections until the coroutine is cancelled.
        The server is closed when the coroutine is cancelled.
        """
        raise NotImplementedError
    async def wait_closed(self):
        """Coroutine to wait until service is closed."""
        raise NotImplementedError
    async def __aenter__(self):
        return self
    async def __aexit__(self, *exc):
        self.close()
        await self.wait_closed()
 class AbstractEventLoop:
    """Abstract event loop."""
    # Running and stopping the event loop.
    def run_forever(self):
        """Run the event loop until stop() is called."""
        raise NotImplementedError
    def run_until_complete(self, future):
        """Run the event loop until a Future is done.
        Return the Future's result, or raise its exception.
        """
        raise NotImplementedError
    def stop(self):
        """Stop the event loop as soon as reasonable.
        Exactly how soon that is may depend on the implementation, but
        no more I/O callbacks should be scheduled.
        """
        raise NotImplementedError
    def is_running(self):
        """Return whether the event loop is currently running."""
        raise NotImplementedError
    def is_closed(self):
        """Returns True if the event loop was closed."""
        raise NotImplementedError
    def close(self):
        """Close the loop.
        The loop should not be running.
        This is idempotent and irreversible.
        No other methods should be called after this one.
        """
        raise NotImplementedError
    async def shutdown_asyncgens(self):
        """Shutdown all active asynchronous generators."""
        raise NotImplementedError
    # Methods scheduling callbacks.  All these return Handles.
    def _timer_handle_cancelled(self, handle):
        """Notification that a TimerHandle has been cancelled."""
        raise NotImplementedError
    def call_soon(self, callback, *args):
        return self.call_later(0, callback, *args)
    def call_later(self, delay, callback, *args):
        raise NotImplementedError
    def call_at(self, when, callback, *args):
        raise NotImplementedError
    def time(self):
        raise NotImplementedError
    def create_future(self):
        raise NotImplementedError
    # Method scheduling a coroutine object: create a task.
    def create_task(self, coro):
        raise NotImplementedError
    # Methods for interacting with threads.
    def call_soon_threadsafe(self, callback, *args):
        raise NotImplementedError
    async def run_in_executor(self, executor, func, *args):
        raise NotImplementedError
    def set_default_executor(self, executor):
        raise NotImplementedError
    # Network I/O methods returning Futures.
    async def getaddrinfo(self, host, port, *,
                          family=0, type=0, proto=0, flags=0):
        raise NotImplementedError
    async def getnameinfo(self, sockaddr, flags=0):
        raise NotImplementedError
    async def create_connection(
            self, protocol_factory, host=None, port=None,
            *, ssl=None, family=0, proto=0,
            flags=0, sock=None, local_addr=None,
            server_hostname=None,
            ssl_handshake_timeout=None):
        raise NotImplementedError
    async def create_server(
            self, protocol_factory, host=None, port=None,
            *, family=socket.AF_UNSPEC,
            flags=socket.AI_PASSIVE, sock=None, backlog=100,
            ssl=None, reuse_address=None, reuse_port=None,
            ssl_handshake_timeout=None,
            start_serving=True):
        """A coroutine which creates a TCP server bound to host and port.
        The return value is a Server object which can be used to stop
        the service.
        If host is an empty string or None all interfaces are assumed
        and a list of multiple sockets will be returned (most likely
        one for IPv4 and another one for IPv6). The host parameter can also be
        a sequence (e.g. list) of hosts to bind to.
        family can be set to either AF_INET or AF_INET6 to force the
        socket to use IPv4 or IPv6. If not set it will be determined
        from host (defaults to AF_UNSPEC).
        flags is a bitmask for getaddrinfo().
        sock can optionally be specified in order to use a preexisting
        socket object.
        backlog is the maximum number of queued connections passed to
        listen() (defaults to 100).
        ssl can be set to an SSLContext to enable SSL over the
        accepted connections.
        reuse_address tells the kernel to reuse a local socket in
        TIME_WAIT state, without waiting for its natural timeout to
        expire. If not specified will automatically be set to True on
        UNIX.
        reuse_port tells the kernel to allow this endpoint to be bound to
        the same port as other existing endpoints are bound to, so long as
        they all set this flag when being created. This option is not
        supported on Windows.
        ssl_handshake_timeout is the time in seconds that an SSL server
        will wait for completion of the SSL handshake before aborting the
        connection. Default is 60s.
        start_serving set to True (default) causes the created server
        to start accepting connections immediately.  When set to False,
        the user should await Server.start_serving() or Server.serve_forever()
        to make the server to start accepting connections.
        """
        raise NotImplementedError
    async def sendfile(self, transport, file, offset=0, count=None,
                       *, fallback=True):
        """Send a file through a transport.
        Return an amount of sent bytes.
        """
        raise NotImplementedError
    async def start_tls(self, transport, protocol, sslcontext, *,
                        server_side=False,
                        server_hostname=None,
                        ssl_handshake_timeout=None):
        """Upgrade a transport to TLS.
        Return a new transport that *protocol* should start using
        immediately.
        """
        raise NotImplementedError
    async def create_unix_connection(
            self, protocol_factory, path=None, *,
            ssl=None, sock=None,
            server_hostname=None,
            ssl_handshake_timeout=None):
        raise NotImplementedError
    async def create_unix_server(
            self, protocol_factory, path=None, *,
            sock=None, backlog=100, ssl=None,
            ssl_handshake_timeout=None,
            start_serving=True):
        """A coroutine which creates a UNIX Domain Socket server.
        The return value is a Server object, which can be used to stop
        the service.
        path is a str, representing a file systsem path to bind the
        server socket to.
        sock can optionally be specified in order to use a preexisting
        socket object.
        backlog is the maximum number of queued connections passed to
        listen() (defaults to 100).
        ssl can be set to an SSLContext to enable SSL over the
        accepted connections.
        ssl_handshake_timeout is the time in seconds that an SSL server
        will wait for the SSL handshake to complete (defaults to 60s).
        start_serving set to True (default) causes the created server
        to start accepting connections immediately.  When set to False,
        the user should await Server.start_serving() or Server.serve_forever()
        to make the server to start accepting connections.
        """
        raise NotImplementedError
    async def create_datagram_endpoint(self, protocol_factory,
                                       local_addr=None, remote_addr=None, *,
                                       family=0, proto=0, flags=0,
                                       reuse_address=None, reuse_port=None,
                                       allow_broadcast=None, sock=None):
        """A coroutine which creates a datagram endpoint.
        This method will try to establish the endpoint in the background.
        When successful, the coroutine returns a (transport, protocol) pair.
        protocol_factory must be a callable returning a protocol instance.
        socket family AF_INET, socket.AF_INET6 or socket.AF_UNIX depending on
        host (or family if specified), socket type SOCK_DGRAM.
        reuse_address tells the kernel to reuse a local socket in
        TIME_WAIT state, without waiting for its natural timeout to
        expire. If not specified it will automatically be set to True on
        UNIX.
        reuse_port tells the kernel to allow this endpoint to be bound to
        the same port as other existing endpoints are bound to, so long as
        they all set this flag when being created. This option is not
        supported on Windows and some UNIX's. If the
        :py:data:`~socket.SO_REUSEPORT` constant is not defined then this
        capability is unsupported.
        allow_broadcast tells the kernel to allow this endpoint to send
        messages to the broadcast address.
        sock can optionally be specified in order to use a preexisting
        socket object.
        """
        raise NotImplementedError
    # Pipes and subprocesses.
    async def connect_read_pipe(self, protocol_factory, pipe):
        """Register read pipe in event loop. Set the pipe to non-blocking mode.
        protocol_factory should instantiate object with Protocol interface.
        pipe is a file-like object.
        Return pair (transport, protocol), where transport supports the
        ReadTransport interface."""
        # The reason to accept file-like object instead of just file descriptor
        # is: we need to own pipe and close it at transport finishing
        # Can got complicated errors if pass f.fileno(),
        # close fd in pipe transport then close f and vise versa.
        raise NotImplementedError
    async def connect_write_pipe(self, protocol_factory, pipe):
        """Register write pipe in event loop.
        protocol_factory should instantiate object with BaseProtocol interface.
        Pipe is file-like object already switched to nonblocking.
        Return pair (transport, protocol), where transport support
        WriteTransport interface."""
        # The reason to accept file-like object instead of just file descriptor
        # is: we need to own pipe and close it at transport finishing
        # Can got complicated errors if pass f.fileno(),
        # close fd in pipe transport then close f and vise versa.
        raise NotImplementedError
    async def subprocess_shell(self, protocol_factory, cmd, *,
                               stdin=subprocess.PIPE,
                               stdout=subprocess.PIPE,
                               stderr=subprocess.PIPE,
                               **kwargs):
        raise NotImplementedError
    async def subprocess_exec(self, protocol_factory, *args,
                              stdin=subprocess.PIPE,
                              stdout=subprocess.PIPE,
                              stderr=subprocess.PIPE,
                              **kwargs):
        raise NotImplementedError
    # Ready-based callback registration methods.
    # The add_*() methods return None.
    # The remove_*() methods return True if something was removed,
    # False if there was nothing to delete.
    def add_reader(self, fd, callback, *args):
        raise NotImplementedError
    def remove_reader(self, fd):
        raise NotImplementedError
    def add_writer(self, fd, callback, *args):
        raise NotImplementedError
    def remove_writer(self, fd):
        raise NotImplementedError
    # Completion based I/O methods returning Futures.
    async def sock_recv(self, sock, nbytes):
        raise NotImplementedError
    async def sock_recv_into(self, sock, buf):
        raise NotImplementedError
    async def sock_sendall(self, sock, data):
        raise NotImplementedError
    async def sock_connect(self, sock, address):
        raise NotImplementedError
    async def sock_accept(self, sock):
        raise NotImplementedError
    async def sock_sendfile(self, sock, file, offset=0, count=None,
                            *, fallback=None):
        raise NotImplementedError
    # Signal handling.
    def add_signal_handler(self, sig, callback, *args):
        raise NotImplementedError
    def remove_signal_handler(self, sig):
        raise NotImplementedError
    # Task factory.
    def set_task_factory(self, factory):
        raise NotImplementedError
    def get_task_factory(self):
        raise NotImplementedError
    # Error handlers.
    def get_exception_handler(self):
        raise NotImplementedError
    def set_exception_handler(self, handler):
        raise NotImplementedError
    def default_exception_handler(self, context):
        raise NotImplementedError
    def call_exception_handler(self, context):
        raise NotImplementedError
    # Debug flag management.
    def get_debug(self):
        raise NotImplementedError
    def set_debug(self, enabled):
        raise NotImplementedError
 class AbstractEventLoopPolicy:
    """Abstract policy for accessing the event loop."""
    def get_event_loop(self):
        """Get the event loop for the current context.
        Returns an event loop object implementing the BaseEventLoop interface,
        or raises an exception in case no event loop has been set for the
        current context and the current policy does not specify to create one.
        It should never return None."""
        raise NotImplementedError
    def set_event_loop(self, loop):
        """Set the event loop for the current context to loop."""
        raise NotImplementedError
    def new_event_loop(self):
        """Create and return a new event loop object according to this
        policy's rules. If there's need to set this loop as the event loop for
        the current context, set_event_loop must be called explicitly."""
        raise NotImplementedError
    # Child processes handling (Unix only).
    def get_child_watcher(self):
        "Get the watcher for child processes."
        raise NotImplementedError
    def set_child_watcher(self, watcher):
        """Set the watcher for child processes."""
        raise NotImplementedError
 class BaseDefaultEventLoopPolicy(AbstractEventLoopPolicy):
    """Default policy implementation for accessing the event loop.
    In this policy, each thread has its own event loop.  However, we
    only automatically create an event loop by default for the main
    thread; other threads by default have no event loop.
    Other policies may have different rules (e.g. a single global
    event loop, or automatically creating an event loop per thread, or
    using some other notion of context to which an event loop is
    associated).
    """
    _loop_factory = None
    class _Local(threading.local):
        _loop = None
        _set_called = False
    def __init__(self):
        self._local = self._Local()
    def get_event_loop(self):
        """Get the event loop.
        This may be None or an instance of EventLoop.
        """
        if (self._local._loop is None and
                not self._local._set_called and
                isinstance(threading.current_thread(), threading._MainThread)):
            self.set_event_loop(self.new_event_loop())
        if self._local._loop is None:
            raise RuntimeError('There is no current event loop in thread %r.'
                               % threading.current_thread().name)
        return self._local._loop
    def set_event_loop(self, loop):
        """Set the event loop."""
        self._local._set_called = True
        assert loop is None or isinstance(loop, AbstractEventLoop)
        self._local._loop = loop
    def new_event_loop(self):
        """Create a new event loop.
        You must call set_event_loop() to make this the current event
        loop.
        """
        return self._loop_factory()
 # Event loop policy.  The policy itself is always global, even if the
 # policy's rules say that there is an event loop per thread (or other
 # notion of context).  The default policy is installed by the first
 # call to get_event_loop_policy().
 _event_loop_policy = None
 # Lock for protecting the on-the-fly creation of the event loop policy.
 _lock = threading.Lock()
 # A TLS for the running event loop, used by _get_running_loop.
 class _RunningLoop(threading.local):
    loop_pid = (None, None)
 _running_loop = _RunningLoop()
 def get_running_loop():
    """Return the running event loop.  Raise a RuntimeError if there is none.
    This function is thread-specific.
    """
    # NOTE: this function is implemented in C (see _asynciomodule.c)
    loop = _get_running_loop()
    if loop is None:
        raise RuntimeError('no running event loop')
    return loop
 def _get_running_loop():
    """Return the running event loop or None.
    This is a low-level function intended to be used by event loops.
    This function is thread-specific.
    """
    # NOTE: this function is implemented in C (see _asynciomodule.c)
    running_loop, pid = _running_loop.loop_pid
    if running_loop is not None and pid == os.getpid():
        return running_loop
 def _set_running_loop(loop):
    """Set the running event loop.
    This is a low-level function intended to be used by event loops.
    This function is thread-specific.
    """
    # NOTE: this function is implemented in C (see _asynciomodule.c)
    _running_loop.loop_pid = (loop, os.getpid())
 def _init_event_loop_policy():
    global _event_loop_policy
    with _lock:
        if _event_loop_policy is None:  # pragma: no branch
            from . import DefaultEventLoopPolicy
            _event_loop_policy = DefaultEventLoopPolicy()
 def get_event_loop_policy():
    """Get the current event loop policy."""
    if _event_loop_policy is None:
        _init_event_loop_policy()
    return _event_loop_policy
 def set_event_loop_policy(policy):
    """Set the current event loop policy.
    If policy is None, the default policy is restored."""
    global _event_loop_policy
    assert policy is None or isinstance(policy, AbstractEventLoopPolicy)
    _event_loop_policy = policy
 def get_event_loop():
    """Return an asyncio event loop.
    When called from a coroutine or a callback (e.g. scheduled with call_soon
    or similar API), this function will always return the running event loop.
    If there is no running event loop set, the function will return
    the result of `get_event_loop_policy().get_event_loop()` call.
    """
    # NOTE: this function is implemented in C (see _asynciomodule.c)
    current_loop = _get_running_loop()
    if current_loop is not None:
        return current_loop
    return get_event_loop_policy().get_event_loop()
 def set_event_loop(loop):
    """Equivalent to calling get_event_loop_policy().set_event_loop(loop)."""
    get_event_loop_policy().set_event_loop(loop)
 def new_event_loop():
    """Equivalent to calling get_event_loop_policy().new_event_loop()."""
    return get_event_loop_policy().new_event_loop()
 def get_child_watcher():
    """Equivalent to calling get_event_loop_policy().get_child_watcher()."""
    return get_event_loop_policy().get_child_watcher()
 def set_child_watcher(watcher):
    """Equivalent to calling
    get_event_loop_policy().set_child_watcher(watcher)."""
    return get_event_loop_policy().set_child_watcher(watcher)
 # Alias pure-Python implementations for testing purposes.
 _py__get_running_loop = _get_running_loop
 _py__set_running_loop = _set_running_loop
 _py_get_running_loop = get_running_loop
 _py_get_event_loop = get_event_loop
 try:
    # get_event_loop() is one of the most frequently called
    # functions in asyncio.  Pure Python implementation is
    # about 4 times slower than C-accelerated.
    from _asyncio import (_get_running_loop, _set_running_loop,
                          get_running_loop, get_event_loop)
 except ImportError:
    pass
 else:
    # Alias C implementations for testing purposes.
    _c__get_running_loop = _get_running_loop
    _c__set_running_loop = _set_running_loop
    _c_get_running_loop = get_running_loop
    _c_get_event_loop = get_event_loop
--- a/Lib/asyncio/format_helpers.py
+++ b/Lib/asyncio/format_helpers.py
@ -0,0 +1,76 @@
 import functools
 import inspect
 import reprlib
 import sys
 import traceback
 from . import constants
 def _get_function_source(func):
    func = inspect.unwrap(func)
    if inspect.isfunction(func):
        code = func.__code__
        return (code.co_filename, code.co_firstlineno)
    if isinstance(func, functools.partial):
        return _get_function_source(func.func)
    if isinstance(func, functools.partialmethod):
        return _get_function_source(func.func)
    return None
 def _format_callback_source(func, args):
    func_repr = _format_callback(func, args, None)
    source = _get_function_source(func)
    if source:
        func_repr += f' at {source[0]}:{source[1]}'
    return func_repr
 def _format_args_and_kwargs(args, kwargs):
    """Format function arguments and keyword arguments.
    Special case for a single parameter: ('hello',) is formatted as ('hello').
    """
    # use reprlib to limit the length of the output
    items = []
    if args:
        items.extend(reprlib.repr(arg) for arg in args)
    if kwargs:
        items.extend(f'{k}={reprlib.repr(v)}' for k, v in kwargs.items())
    return '({})'.format(', '.join(items))
 def _format_callback(func, args, kwargs, suffix=''):
    if isinstance(func, functools.partial):
        suffix = _format_args_and_kwargs(args, kwargs) + suffix
        return _format_callback(func.func, func.args, func.keywords, suffix)
    if hasattr(func, '__qualname__') and func.__qualname__:
        func_repr = func.__qualname__
    elif hasattr(func, '__name__') and func.__name__:
        func_repr = func.__name__
    else:
        func_repr = repr(func)
    func_repr += _format_args_and_kwargs(args, kwargs)
    if suffix:
        func_repr += suffix
    return func_repr
 def extract_stack(f=None, limit=None):
    """Replacement for traceback.extract_stack() that only does the
    necessary work for asyncio debug mode.
    """
    if f is None:
        f = sys._getframe().f_back
    if limit is None:
        # Limit the amount of work to a reasonable amount, as extract_stack()
        # can be called for each coroutine and future in debug mode.
        limit = constants.DEBUG_STACK_DEPTH
    stack = traceback.StackSummary.extract(traceback.walk_stack(f),
                                           limit=limit,
                                           lookup_lines=False)
    stack.reverse()
    return stack
--- a/Lib/asyncio/futures.py
+++ b/Lib/asyncio/futures.py
@ -0,0 +1,387 @@
 """A Future class similar to the one in PEP 3148."""
 __all__ = (
    'CancelledError', 'TimeoutError', 'InvalidStateError',
    'Future', 'wrap_future', 'isfuture',
 )
 import concurrent.futures
 import contextvars
 import logging
 import sys
 from . import base_futures
 from . import events
 from . import format_helpers
 CancelledError = base_futures.CancelledError
 InvalidStateError = base_futures.InvalidStateError
 TimeoutError = base_futures.TimeoutError
 isfuture = base_futures.isfuture
 _PENDING = base_futures._PENDING
 _CANCELLED = base_futures._CANCELLED
 _FINISHED = base_futures._FINISHED
 STACK_DEBUG = logging.DEBUG - 1  # heavy-duty debugging
 class Future:
    """This class is *almost* compatible with concurrent.futures.Future.
    Differences:
    - This class is not thread-safe.
    - result() and exception() do not take a timeout argument and
      raise an exception when the future isn't done yet.
    - Callbacks registered with add_done_callback() are always called
      via the event loop's call_soon().
    - This class is not compatible with the wait() and as_completed()
      methods in the concurrent.futures package.
    (In Python 3.4 or later we may be able to unify the implementations.)
    """
    # Class variables serving as defaults for instance variables.
    _state = _PENDING
    _result = None
    _exception = None
    _loop = None
    _source_traceback = None
    # This field is used for a dual purpose:
    # - Its presence is a marker to declare that a class implements
    #   the Future protocol (i.e. is intended to be duck-type compatible).
    #   The value must also be not-None, to enable a subclass to declare
    #   that it is not compatible by setting this to None.
    # - It is set by __iter__() below so that Task._step() can tell
    #   the difference between
    #   `await Future()` or`yield from Future()` (correct) vs.
    #   `yield Future()` (incorrect).
    _asyncio_future_blocking = False
    __log_traceback = False
    def __init__(self, *, loop=None):
        """Initialize the future.
        The optional event_loop argument allows explicitly setting the event
        loop object used by the future. If it's not provided, the future uses
        the default event loop.
        """
        if loop is None:
            self._loop = events.get_event_loop()
        else:
            self._loop = loop
        self._callbacks = []
        if self._loop.get_debug():
            self._source_traceback = format_helpers.extract_stack(
                sys._getframe(1))
    _repr_info = base_futures._future_repr_info
    def __repr__(self):
        return '<{} {}>'.format(self.__class__.__name__,
                                ' '.join(self._repr_info()))
    def __del__(self):
        if not self.__log_traceback:
            # set_exception() was not called, or result() or exception()
            # has consumed the exception
            return
        exc = self._exception
        context = {
            'message':
                f'{self.__class__.__name__} exception was never retrieved',
            'exception': exc,
            'future': self,
        }
        if self._source_traceback:
            context['source_traceback'] = self._source_traceback
        self._loop.call_exception_handler(context)
    @property
    def _log_traceback(self):
        return self.__log_traceback
    @_log_traceback.setter
    def _log_traceback(self, val):
        if bool(val):
            raise ValueError('_log_traceback can only be set to False')
        self.__log_traceback = False
    def get_loop(self):
        """Return the event loop the Future is bound to."""
        return self._loop
    def cancel(self):
        """Cancel the future and schedule callbacks.
        If the future is already done or cancelled, return False.  Otherwise,
        change the future's state to cancelled, schedule the callbacks and
        return True.
        """
        self.__log_traceback = False
        if self._state != _PENDING:
            return False
        self._state = _CANCELLED
        self.__schedule_callbacks()
        return True
    def __schedule_callbacks(self):
        """Internal: Ask the event loop to call all callbacks.
        The callbacks are scheduled to be called as soon as possible. Also
        clears the callback list.
        """
        callbacks = self._callbacks[:]
        if not callbacks:
            return
        self._callbacks[:] = []
        for callback, ctx in callbacks:
            self._loop.call_soon(callback, self, context=ctx)
    def cancelled(self):
        """Return True if the future was cancelled."""
        return self._state == _CANCELLED
    # Don't implement running(); see http://bugs.python.org/issue18699
    def done(self):
        """Return True if the future is done.
        Done means either that a result / exception are available, or that the
        future was cancelled.
        """
        return self._state != _PENDING
    def result(self):
        """Return the result this future represents.
        If the future has been cancelled, raises CancelledError.  If the
        future's result isn't yet available, raises InvalidStateError.  If
        the future is done and has an exception set, this exception is raised.
        """
        if self._state == _CANCELLED:
            raise CancelledError
        if self._state != _FINISHED:
            raise InvalidStateError('Result is not ready.')
        self.__log_traceback = False
        if self._exception is not None:
            raise self._exception
        return self._result
    def exception(self):
        """Return the exception that was set on this future.
        The exception (or None if no exception was set) is returned only if
        the future is done.  If the future has been cancelled, raises
        CancelledError.  If the future isn't done yet, raises
        InvalidStateError.
        """
        if self._state == _CANCELLED:
            raise CancelledError
        if self._state != _FINISHED:
            raise InvalidStateError('Exception is not set.')
        self.__log_traceback = False
        return self._exception
    def add_done_callback(self, fn, *, context=None):
        """Add a callback to be run when the future becomes done.
        The callback is called with a single argument - the future object. If
        the future is already done when this is called, the callback is
        scheduled with call_soon.
        """
        if self._state != _PENDING:
            self._loop.call_soon(fn, self, context=context)
        else:
            if context is None:
                context = contextvars.copy_context()
            self._callbacks.append((fn, context))
    # New method not in PEP 3148.
    def remove_done_callback(self, fn):
        """Remove all instances of a callback from the "call when done" list.
        Returns the number of callbacks removed.
        """
        filtered_callbacks = [(f, ctx)
                              for (f, ctx) in self._callbacks
                              if f != fn]
        removed_count = len(self._callbacks) - len(filtered_callbacks)
        if removed_count:
            self._callbacks[:] = filtered_callbacks
        return removed_count
    # So-called internal methods (note: no set_running_or_notify_cancel()).
    def set_result(self, result):
        """Mark the future done and set its result.
        If the future is already done when this method is called, raises
        InvalidStateError.
        """
        if self._state != _PENDING:
            raise InvalidStateError('{}: {!r}'.format(self._state, self))
        self._result = result
        self._state = _FINISHED
        self.__schedule_callbacks()
    def set_exception(self, exception):
        """Mark the future done and set an exception.
        If the future is already done when this method is called, raises
        InvalidStateError.
        """
        if self._state != _PENDING:
            raise InvalidStateError('{}: {!r}'.format(self._state, self))
        if isinstance(exception, type):
            exception = exception()
        if type(exception) is StopIteration:
            raise TypeError("StopIteration interacts badly with generators "
                            "and cannot be raised into a Future")
        self._exception = exception
        self._state = _FINISHED
        self.__schedule_callbacks()
        self.__log_traceback = True
    def __await__(self):
        if not self.done():
            self._asyncio_future_blocking = True
            yield self  # This tells Task to wait for completion.
        if not self.done():
            raise RuntimeError("await wasn't used with future")
        return self.result()  # May raise too.
    __iter__ = __await__  # make compatible with 'yield from'.
 # Needed for testing purposes.
 _PyFuture = Future
 def _get_loop(fut):
    # Tries to call Future.get_loop() if it's available.
    # Otherwise fallbacks to using the old '_loop' property.
    try:
        get_loop = fut.get_loop
    except AttributeError:
        pass
    else:
        return get_loop()
    return fut._loop
 def _set_result_unless_cancelled(fut, result):
    """Helper setting the result only if the future was not cancelled."""
    if fut.cancelled():
        return
    fut.set_result(result)
 def _set_concurrent_future_state(concurrent, source):
    """Copy state from a future to a concurrent.futures.Future."""
    assert source.done()
    if source.cancelled():
        concurrent.cancel()
    if not concurrent.set_running_or_notify_cancel():
        return
    exception = source.exception()
    if exception is not None:
        concurrent.set_exception(exception)
    else:
        result = source.result()
        concurrent.set_result(result)
 def _copy_future_state(source, dest):
    """Internal helper to copy state from another Future.
    The other Future may be a concurrent.futures.Future.
    """
    assert source.done()
    if dest.cancelled():
        return
    assert not dest.done()
    if source.cancelled():
        dest.cancel()
    else:
        exception = source.exception()
        if exception is not None:
            dest.set_exception(exception)
        else:
            result = source.result()
            dest.set_result(result)
 def _chain_future(source, destination):
    """Chain two futures so that when one completes, so does the other.
    The result (or exception) of source will be copied to destination.
    If destination is cancelled, source gets cancelled too.
    Compatible with both asyncio.Future and concurrent.futures.Future.
    """
    if not isfuture(source) and not isinstance(source,
                                               concurrent.futures.Future):
        raise TypeError('A future is required for source argument')
    if not isfuture(destination) and not isinstance(destination,
                                                    concurrent.futures.Future):
        raise TypeError('A future is required for destination argument')
    source_loop = _get_loop(source) if isfuture(source) else None
    dest_loop = _get_loop(destination) if isfuture(destination) else None
    def _set_state(future, other):
        if isfuture(future):
            _copy_future_state(other, future)
        else:
            _set_concurrent_future_state(future, other)
    def _call_check_cancel(destination):
        if destination.cancelled():
            if source_loop is None or source_loop is dest_loop:
                source.cancel()
            else:
                source_loop.call_soon_threadsafe(source.cancel)
    def _call_set_state(source):
        if (destination.cancelled() and
                dest_loop is not None and dest_loop.is_closed()):
            return
        if dest_loop is None or dest_loop is source_loop:
            _set_state(destination, source)
        else:
            dest_loop.call_soon_threadsafe(_set_state, destination, source)
    destination.add_done_callback(_call_check_cancel)
    source.add_done_callback(_call_set_state)
 def wrap_future(future, *, loop=None):
    """Wrap concurrent.futures.Future object."""
    if isfuture(future):
        return future
    assert isinstance(future, concurrent.futures.Future), \
        f'concurrent.futures.Future is expected, got {future!r}'
    if loop is None:
        loop = events.get_event_loop()
    new_future = loop.create_future()
    _chain_future(future, new_future)
    return new_future
 try:
    import _asyncio
 except ImportError:
    pass
 else:
    # _CFuture is needed for tests.
    Future = _CFuture = _asyncio.Future
--- a/Lib/asyncio/locks.py
+++ b/Lib/asyncio/locks.py
@ -0,0 +1,507 @@
 """Synchronization primitives."""
 __all__ = ('Lock', 'Event', 'Condition', 'Semaphore', 'BoundedSemaphore')
 import collections
 import warnings
 from . import events
 from . import futures
 from .coroutines import coroutine
 class _ContextManager:
    """Context manager.
    This enables the following idiom for acquiring and releasing a
    lock around a block:
        with (yield from lock):
            <block>
    while failing loudly when accidentally using:
        with lock:
            <block>
    Deprecated, use 'async with' statement:
        async with lock:
            <block>
    """
    def __init__(self, lock):
        self._lock = lock
    def __enter__(self):
        # We have no use for the "as ..."  clause in the with
        # statement for locks.
        return None
    def __exit__(self, *args):
        try:
            self._lock.release()
        finally:
            self._lock = None  # Crudely prevent reuse.
 class _ContextManagerMixin:
    def __enter__(self):
        raise RuntimeError(
            '"yield from" should be used as context manager expression')
    def __exit__(self, *args):
        # This must exist because __enter__ exists, even though that
        # always raises; that's how the with-statement works.
        pass
    @coroutine
    def __iter__(self):
        # This is not a coroutine.  It is meant to enable the idiom:
        #
        #     with (yield from lock):
        #         <block>
        #
        # as an alternative to:
        #
        #     yield from lock.acquire()
        #     try:
        #         <block>
        #     finally:
        #         lock.release()
        # Deprecated, use 'async with' statement:
        #     async with lock:
        #         <block>
        warnings.warn("'with (yield from lock)' is deprecated "
                      "use 'async with lock' instead",
                      DeprecationWarning, stacklevel=2)
        yield from self.acquire()
        return _ContextManager(self)
    async def __acquire_ctx(self):
        await self.acquire()
        return _ContextManager(self)
    def __await__(self):
        warnings.warn("'with await lock' is deprecated "
                      "use 'async with lock' instead",
                      DeprecationWarning, stacklevel=2)
        # To make "with await lock" work.
        return self.__acquire_ctx().__await__()
    async def __aenter__(self):
        await self.acquire()
        # We have no use for the "as ..."  clause in the with
        # statement for locks.
        return None
    async def __aexit__(self, exc_type, exc, tb):
        self.release()
 class Lock(_ContextManagerMixin):
    """Primitive lock objects.
    A primitive lock is a synchronization primitive that is not owned
    by a particular coroutine when locked.  A primitive lock is in one
    of two states, 'locked' or 'unlocked'.
    It is created in the unlocked state.  It has two basic methods,
    acquire() and release().  When the state is unlocked, acquire()
    changes the state to locked and returns immediately.  When the
    state is locked, acquire() blocks until a call to release() in
    another coroutine changes it to unlocked, then the acquire() call
    resets it to locked and returns.  The release() method should only
    be called in the locked state; it changes the state to unlocked
    and returns immediately.  If an attempt is made to release an
    unlocked lock, a RuntimeError will be raised.
    When more than one coroutine is blocked in acquire() waiting for
    the state to turn to unlocked, only one coroutine proceeds when a
    release() call resets the state to unlocked; first coroutine which
    is blocked in acquire() is being processed.
    acquire() is a coroutine and should be called with 'await'.
    Locks also support the asynchronous context management protocol.
    'async with lock' statement should be used.
    Usage:
        lock = Lock()
        ...
        await lock.acquire()
        try:
            ...
        finally:
            lock.release()
    Context manager usage:
        lock = Lock()
        ...
        async with lock:
             ...
    Lock objects can be tested for locking state:
        if not lock.locked():
           await lock.acquire()
        else:
           # lock is acquired
           ...
    """
    def __init__(self, *, loop=None):
        self._waiters = collections.deque()
        self._locked = False
        if loop is not None:
            self._loop = loop
        else:
            self._loop = events.get_event_loop()
    def __repr__(self):
        res = super().__repr__()
        extra = 'locked' if self._locked else 'unlocked'
        if self._waiters:
            extra = f'{extra}, waiters:{len(self._waiters)}'
        return f'<{res[1:-1]} [{extra}]>'
    def locked(self):
        """Return True if lock is acquired."""
        return self._locked
    async def acquire(self):
        """Acquire a lock.
        This method blocks until the lock is unlocked, then sets it to
        locked and returns True.
        """
        if not self._locked and all(w.cancelled() for w in self._waiters):
            self._locked = True
            return True
        fut = self._loop.create_future()
        self._waiters.append(fut)
        # Finally block should be called before the CancelledError
        # handling as we don't want CancelledError to call
        # _wake_up_first() and attempt to wake up itself.
        try:
            try:
                await fut
            finally:
                self._waiters.remove(fut)
        except futures.CancelledError:
            if not self._locked:
                self._wake_up_first()
            raise
        self._locked = True
        return True
    def release(self):
        """Release a lock.
        When the lock is locked, reset it to unlocked, and return.
        If any other coroutines are blocked waiting for the lock to become
        unlocked, allow exactly one of them to proceed.
        When invoked on an unlocked lock, a RuntimeError is raised.
        There is no return value.
        """
        if self._locked:
            self._locked = False
            self._wake_up_first()
        else:
            raise RuntimeError('Lock is not acquired.')
    def _wake_up_first(self):
        """Wake up the first waiter if it isn't done."""
        try:
            fut = next(iter(self._waiters))
        except StopIteration:
            return
        # .done() necessarily means that a waiter will wake up later on and
        # either take the lock, or, if it was cancelled and lock wasn't
        # taken already, will hit this again and wake up a new waiter.
        if not fut.done():
            fut.set_result(True)
 class Event:
    """Asynchronous equivalent to threading.Event.
    Class implementing event objects. An event manages a flag that can be set
    to true with the set() method and reset to false with the clear() method.
    The wait() method blocks until the flag is true. The flag is initially
    false.
    """
    def __init__(self, *, loop=None):
        self._waiters = collections.deque()
        self._value = False
        if loop is not None:
            self._loop = loop
        else:
            self._loop = events.get_event_loop()
    def __repr__(self):
        res = super().__repr__()
        extra = 'set' if self._value else 'unset'
        if self._waiters:
            extra = f'{extra}, waiters:{len(self._waiters)}'
        return f'<{res[1:-1]} [{extra}]>'
    def is_set(self):
        """Return True if and only if the internal flag is true."""
        return self._value
    def set(self):
        """Set the internal flag to true. All coroutines waiting for it to
        become true are awakened. Coroutine that call wait() once the flag is
        true will not block at all.
        """
        if not self._value:
            self._value = True
            for fut in self._waiters:
                if not fut.done():
                    fut.set_result(True)
    def clear(self):
        """Reset the internal flag to false. Subsequently, coroutines calling
        wait() will block until set() is called to set the internal flag
        to true again."""
        self._value = False
    async def wait(self):
        """Block until the internal flag is true.
        If the internal flag is true on entry, return True
        immediately.  Otherwise, block until another coroutine calls
        set() to set the flag to true, then return True.
        """
        if self._value:
            return True
        fut = self._loop.create_future()
        self._waiters.append(fut)
        try:
            await fut
            return True
        finally:
            self._waiters.remove(fut)
 class Condition(_ContextManagerMixin):
    """Asynchronous equivalent to threading.Condition.
    This class implements condition variable objects. A condition variable
    allows one or more coroutines to wait until they are notified by another
    coroutine.
    A new Lock object is created and used as the underlying lock.
    """
    def __init__(self, lock=None, *, loop=None):
        if loop is not None:
            self._loop = loop
        else:
            self._loop = events.get_event_loop()
        if lock is None:
            lock = Lock(loop=self._loop)
        elif lock._loop is not self._loop:
            raise ValueError("loop argument must agree with lock")
        self._lock = lock
        # Export the lock's locked(), acquire() and release() methods.
        self.locked = lock.locked
        self.acquire = lock.acquire
        self.release = lock.release
        self._waiters = collections.deque()
    def __repr__(self):
        res = super().__repr__()
        extra = 'locked' if self.locked() else 'unlocked'
        if self._waiters:
            extra = f'{extra}, waiters:{len(self._waiters)}'
        return f'<{res[1:-1]} [{extra}]>'
    async def wait(self):
        """Wait until notified.
        If the calling coroutine has not acquired the lock when this
        method is called, a RuntimeError is raised.
        This method releases the underlying lock, and then blocks
        until it is awakened by a notify() or notify_all() call for
        the same condition variable in another coroutine.  Once
        awakened, it re-acquires the lock and returns True.
        """
        if not self.locked():
            raise RuntimeError('cannot wait on un-acquired lock')
        self.release()
        try:
            fut = self._loop.create_future()
            self._waiters.append(fut)
            try:
                await fut
                return True
            finally:
                self._waiters.remove(fut)
        finally:
            # Must reacquire lock even if wait is cancelled
            cancelled = False
            while True:
                try:
                    await self.acquire()
                    break
                except futures.CancelledError:
                    cancelled = True
            if cancelled:
                raise futures.CancelledError
    async def wait_for(self, predicate):
        """Wait until a predicate becomes true.
        The predicate should be a callable which result will be
        interpreted as a boolean value.  The final predicate value is
        the return value.
        """
        result = predicate()
        while not result:
            await self.wait()
            result = predicate()
        return result
    def notify(self, n=1):
        """By default, wake up one coroutine waiting on this condition, if any.
        If the calling coroutine has not acquired the lock when this method
        is called, a RuntimeError is raised.
        This method wakes up at most n of the coroutines waiting for the
        condition variable; it is a no-op if no coroutines are waiting.
        Note: an awakened coroutine does not actually return from its
        wait() call until it can reacquire the lock. Since notify() does
        not release the lock, its caller should.
        """
        if not self.locked():
            raise RuntimeError('cannot notify on un-acquired lock')
        idx = 0
        for fut in self._waiters:
            if idx >= n:
                break
            if not fut.done():
                idx += 1
                fut.set_result(False)
    def notify_all(self):
        """Wake up all threads waiting on this condition. This method acts
        like notify(), but wakes up all waiting threads instead of one. If the
        calling thread has not acquired the lock when this method is called,
        a RuntimeError is raised.
        """
        self.notify(len(self._waiters))
 class Semaphore(_ContextManagerMixin):
    """A Semaphore implementation.
    A semaphore manages an internal counter which is decremented by each
    acquire() call and incremented by each release() call. The counter
    can never go below zero; when acquire() finds that it is zero, it blocks,
    waiting until some other thread calls release().
    Semaphores also support the context management protocol.
    The optional argument gives the initial value for the internal
    counter; it defaults to 1. If the value given is less than 0,
    ValueError is raised.
    """
    def __init__(self, value=1, *, loop=None):
        if value < 0:
            raise ValueError("Semaphore initial value must be >= 0")
        self._value = value
        self._waiters = collections.deque()
        if loop is not None:
            self._loop = loop
        else:
            self._loop = events.get_event_loop()
    def __repr__(self):
        res = super().__repr__()
        extra = 'locked' if self.locked() else f'unlocked, value:{self._value}'
        if self._waiters:
            extra = f'{extra}, waiters:{len(self._waiters)}'
        return f'<{res[1:-1]} [{extra}]>'
    def _wake_up_next(self):
        while self._waiters:
            waiter = self._waiters.popleft()
            if not waiter.done():
                waiter.set_result(None)
                return
    def locked(self):
        """Returns True if semaphore can not be acquired immediately."""
        return self._value == 0
    async def acquire(self):
        """Acquire a semaphore.
        If the internal counter is larger than zero on entry,
        decrement it by one and return True immediately.  If it is
        zero on entry, block, waiting until some other coroutine has
        called release() to make it larger than 0, and then return
        True.
        """
        while self._value <= 0:
            fut = self._loop.create_future()
            self._waiters.append(fut)
            try:
                await fut
            except:
                # See the similar code in Queue.get.
                fut.cancel()
                if self._value > 0 and not fut.cancelled():
                    self._wake_up_next()
                raise
        self._value -= 1
        return True
    def release(self):
        """Release a semaphore, incrementing the internal counter by one.
        When it was zero on entry and another coroutine is waiting for it to
        become larger than zero again, wake up that coroutine.
        """
        self._value += 1
        self._wake_up_next()
 class BoundedSemaphore(Semaphore):
    """A bounded semaphore implementation.
    This raises ValueError in release() if it would increase the value
    above the initial value.
    """
    def __init__(self, value=1, *, loop=None):
        self._bound_value = value
        super().__init__(value, loop=loop)
    def release(self):
        if self._value >= self._bound_value:
            raise ValueError('BoundedSemaphore released too many times')
        super().release()
--- a/Lib/asyncio/log.py
+++ b/Lib/asyncio/log.py
@ -0,0 +1,7 @@
 """Logging configuration."""
 import logging
 # Name the logger after the package.
 logger = logging.getLogger(__package__)
--- a/Lib/asyncio/proactor_events.py
+++ b/Lib/asyncio/proactor_events.py
@ -0,0 +1,696 @@
 """Event loop using a proactor and related classes.
 A proactor is a "notify-on-completion" multiplexer.  Currently a
 proactor is only implemented on Windows with IOCP.
 """
 __all__ = 'BaseProactorEventLoop',
 import io
 import os
 import socket
 import warnings
 from . import base_events
 from . import constants
 from . import events
 from . import futures
 from . import protocols
 from . import sslproto
 from . import transports
 from .log import logger
 class _ProactorBasePipeTransport(transports._FlowControlMixin,
                                 transports.BaseTransport):
    """Base class for pipe and socket transports."""
    def __init__(self, loop, sock, protocol, waiter=None,
                 extra=None, server=None):
        super().__init__(extra, loop)
        self._set_extra(sock)
        self._sock = sock
        self.set_protocol(protocol)
        self._server = server
        self._buffer = None  # None or bytearray.
        self._read_fut = None
        self._write_fut = None
        self._pending_write = 0
        self._conn_lost = 0
        self._closing = False  # Set when close() called.
        self._eof_written = False
        if self._server is not None:
            self._server._attach()
        self._loop.call_soon(self._protocol.connection_made, self)
        if waiter is not None:
            # only wake up the waiter when connection_made() has been called
            self._loop.call_soon(futures._set_result_unless_cancelled,
                                 waiter, None)
    def __repr__(self):
        info = [self.__class__.__name__]
        if self._sock is None:
            info.append('closed')
        elif self._closing:
            info.append('closing')
        if self._sock is not None:
            info.append(f'fd={self._sock.fileno()}')
        if self._read_fut is not None:
            info.append(f'read={self._read_fut!r}')
        if self._write_fut is not None:
            info.append(f'write={self._write_fut!r}')
        if self._buffer:
            info.append(f'write_bufsize={len(self._buffer)}')
        if self._eof_written:
            info.append('EOF written')
        return '<{}>'.format(' '.join(info))
    def _set_extra(self, sock):
        self._extra['pipe'] = sock
    def set_protocol(self, protocol):
        self._protocol = protocol
    def get_protocol(self):
        return self._protocol
    def is_closing(self):
        return self._closing
    def close(self):
        if self._closing:
            return
        self._closing = True
        self._conn_lost += 1
        if not self._buffer and self._write_fut is None:
            self._loop.call_soon(self._call_connection_lost, None)
        if self._read_fut is not None:
            self._read_fut.cancel()
            self._read_fut = None
    def __del__(self):
        if self._sock is not None:
            warnings.warn(f"unclosed transport {self!r}", ResourceWarning,
                          source=self)
            self.close()
    def _fatal_error(self, exc, message='Fatal error on pipe transport'):
        try:
            if isinstance(exc, base_events._FATAL_ERROR_IGNORE):
                if self._loop.get_debug():
                    logger.debug("%r: %s", self, message, exc_info=True)
            else:
                self._loop.call_exception_handler({
                    'message': message,
                    'exception': exc,
                    'transport': self,
                    'protocol': self._protocol,
                })
        finally:
            self._force_close(exc)
    def _force_close(self, exc):
        if self._empty_waiter is not None:
            if exc is None:
                self._empty_waiter.set_result(None)
            else:
                self._empty_waiter.set_exception(exc)
        if self._closing:
            return
        self._closing = True
        self._conn_lost += 1
        if self._write_fut:
            self._write_fut.cancel()
            self._write_fut = None
        if self._read_fut:
            self._read_fut.cancel()
            self._read_fut = None
        self._pending_write = 0
        self._buffer = None
        self._loop.call_soon(self._call_connection_lost, exc)
    def _call_connection_lost(self, exc):
        try:
            self._protocol.connection_lost(exc)
        finally:
            # XXX If there is a pending overlapped read on the other
            # end then it may fail with ERROR_NETNAME_DELETED if we
            # just close our end.  First calling shutdown() seems to
            # cure it, but maybe using DisconnectEx() would be better.
            if hasattr(self._sock, 'shutdown'):
                self._sock.shutdown(socket.SHUT_RDWR)
            self._sock.close()
            self._sock = None
            server = self._server
            if server is not None:
                server._detach()
                self._server = None
    def get_write_buffer_size(self):
        size = self._pending_write
        if self._buffer is not None:
            size += len(self._buffer)
        return size
 class _ProactorReadPipeTransport(_ProactorBasePipeTransport,
                                 transports.ReadTransport):
    """Transport for read pipes."""
    def __init__(self, loop, sock, protocol, waiter=None,
                 extra=None, server=None):
        self._pending_data = None
        self._paused = True
        super().__init__(loop, sock, protocol, waiter, extra, server)
        self._loop.call_soon(self._loop_reading)
        self._paused = False
    def is_reading(self):
        return not self._paused and not self._closing
    def pause_reading(self):
        if self._closing or self._paused:
            return
        self._paused = True
        # bpo-33694: Don't cancel self._read_fut because cancelling an
        # overlapped WSASend() loss silently data with the current proactor
        # implementation.
        #
        # If CancelIoEx() fails with ERROR_NOT_FOUND, it means that WSASend()
        # completed (even if HasOverlappedIoCompleted() returns 0), but
        # Overlapped.cancel() currently silently ignores the ERROR_NOT_FOUND
        # error. Once the overlapped is ignored, the IOCP loop will ignores the
        # completion I/O event and so not read the result of the overlapped
        # WSARecv().
        if self._loop.get_debug():
            logger.debug("%r pauses reading", self)
    def resume_reading(self):
        if self._closing or not self._paused:
            return
        self._paused = False
        if self._read_fut is None:
            self._loop.call_soon(self._loop_reading, None)
        data = self._pending_data
        self._pending_data = None
        if data is not None:
            # Call the protocol methode after calling _loop_reading(),
            # since the protocol can decide to pause reading again.
            self._loop.call_soon(self._data_received, data)
        if self._loop.get_debug():
            logger.debug("%r resumes reading", self)
    def _eof_received(self):
        if self._loop.get_debug():
            logger.debug("%r received EOF", self)
        try:
            keep_open = self._protocol.eof_received()
        except Exception as exc:
            self._fatal_error(
                exc, 'Fatal error: protocol.eof_received() call failed.')
            return
        if not keep_open:
            self.close()
    def _data_received(self, data):
        if self._paused:
            # Don't call any protocol method while reading is paused.
            # The protocol will be called on resume_reading().
            assert self._pending_data is None
            self._pending_data = data
            return
        if not data:
            self._eof_received()
            return
        if isinstance(self._protocol, protocols.BufferedProtocol):
            try:
                protocols._feed_data_to_buffered_proto(self._protocol, data)
            except Exception as exc:
                self._fatal_error(exc,
                                  'Fatal error: protocol.buffer_updated() '
                                  'call failed.')
                return
        else:
            self._protocol.data_received(data)
    def _loop_reading(self, fut=None):
        data = None
        try:
            if fut is not None:
                assert self._read_fut is fut or (self._read_fut is None and
                                                 self._closing)
                self._read_fut = None
                if fut.done():
                    # deliver data later in "finally" clause
                    data = fut.result()
                else:
                    # the future will be replaced by next proactor.recv call
                    fut.cancel()
            if self._closing:
                # since close() has been called we ignore any read data
                data = None
                return
            if data == b'':
                # we got end-of-file so no need to reschedule a new read
                return
            # bpo-33694: buffer_updated() has currently no fast path because of
            # a data loss issue caused by overlapped WSASend() cancellation.
            if not self._paused:
                # reschedule a new read
                self._read_fut = self._loop._proactor.recv(self._sock, 32768)
        except ConnectionAbortedError as exc:
            if not self._closing:
                self._fatal_error(exc, 'Fatal read error on pipe transport')
            elif self._loop.get_debug():
                logger.debug("Read error on pipe transport while closing",
                             exc_info=True)
        except ConnectionResetError as exc:
            self._force_close(exc)
        except OSError as exc:
            self._fatal_error(exc, 'Fatal read error on pipe transport')
        except futures.CancelledError:
            if not self._closing:
                raise
        else:
            if not self._paused:
                self._read_fut.add_done_callback(self._loop_reading)
        finally:
            if data is not None:
                self._data_received(data)
 class _ProactorBaseWritePipeTransport(_ProactorBasePipeTransport,
                                      transports.WriteTransport):
    """Transport for write pipes."""
    _start_tls_compatible = True
    def __init__(self, *args, **kw):
        super().__init__(*args, **kw)
        self._empty_waiter = None
    def write(self, data):
        if not isinstance(data, (bytes, bytearray, memoryview)):
            raise TypeError(
                f"data argument must be a bytes-like object, "
                f"not {type(data).__name__}")
        if self._eof_written:
            raise RuntimeError('write_eof() already called')
        if self._empty_waiter is not None:
            raise RuntimeError('unable to write; sendfile is in progress')
        if not data:
            return
        if self._conn_lost:
            if self._conn_lost >= constants.LOG_THRESHOLD_FOR_CONNLOST_WRITES:
                logger.warning('socket.send() raised exception.')
            self._conn_lost += 1
            return
        # Observable states:
        # 1. IDLE: _write_fut and _buffer both None
        # 2. WRITING: _write_fut set; _buffer None
        # 3. BACKED UP: _write_fut set; _buffer a bytearray
        # We always copy the data, so the caller can't modify it
        # while we're still waiting for the I/O to happen.
        if self._write_fut is None:  # IDLE -> WRITING
            assert self._buffer is None
            # Pass a copy, except if it's already immutable.
            self._loop_writing(data=bytes(data))
        elif not self._buffer:  # WRITING -> BACKED UP
            # Make a mutable copy which we can extend.
            self._buffer = bytearray(data)
            self._maybe_pause_protocol()
        else:  # BACKED UP
            # Append to buffer (also copies).
            self._buffer.extend(data)
            self._maybe_pause_protocol()
    def _loop_writing(self, f=None, data=None):
        try:
            if f is not None and self._write_fut is None and self._closing:
                # XXX most likely self._force_close() has been called, and
                # it has set self._write_fut to None.
                return
            assert f is self._write_fut
            self._write_fut = None
            self._pending_write = 0
            if f:
                f.result()
            if data is None:
                data = self._buffer
                self._buffer = None
            if not data:
                if self._closing:
                    self._loop.call_soon(self._call_connection_lost, None)
                if self._eof_written:
                    self._sock.shutdown(socket.SHUT_WR)
                # Now that we've reduced the buffer size, tell the
                # protocol to resume writing if it was paused.  Note that
                # we do this last since the callback is called immediately
                # and it may add more data to the buffer (even causing the
                # protocol to be paused again).
                self._maybe_resume_protocol()
            else:
                self._write_fut = self._loop._proactor.send(self._sock, data)
                if not self._write_fut.done():
                    assert self._pending_write == 0
                    self._pending_write = len(data)
                    self._write_fut.add_done_callback(self._loop_writing)
                    self._maybe_pause_protocol()
                else:
                    self._write_fut.add_done_callback(self._loop_writing)
            if self._empty_waiter is not None and self._write_fut is None:
                self._empty_waiter.set_result(None)
        except ConnectionResetError as exc:
            self._force_close(exc)
        except OSError as exc:
            self._fatal_error(exc, 'Fatal write error on pipe transport')
    def can_write_eof(self):
        return True
    def write_eof(self):
        self.close()
    def abort(self):
        self._force_close(None)
    def _make_empty_waiter(self):
        if self._empty_waiter is not None:
            raise RuntimeError("Empty waiter is already set")
        self._empty_waiter = self._loop.create_future()
        if self._write_fut is None:
            self._empty_waiter.set_result(None)
        return self._empty_waiter
    def _reset_empty_waiter(self):
        self._empty_waiter = None
 class _ProactorWritePipeTransport(_ProactorBaseWritePipeTransport):
    def __init__(self, *args, **kw):
        super().__init__(*args, **kw)
        self._read_fut = self._loop._proactor.recv(self._sock, 16)
        self._read_fut.add_done_callback(self._pipe_closed)
    def _pipe_closed(self, fut):
        if fut.cancelled():
            # the transport has been closed
            return
        assert fut.result() == b''
        if self._closing:
            assert self._read_fut is None
            return
        assert fut is self._read_fut, (fut, self._read_fut)
        self._read_fut = None
        if self._write_fut is not None:
            self._force_close(BrokenPipeError())
        else:
            self.close()
 class _ProactorDuplexPipeTransport(_ProactorReadPipeTransport,
                                   _ProactorBaseWritePipeTransport,
                                   transports.Transport):
    """Transport for duplex pipes."""
    def can_write_eof(self):
        return False
    def write_eof(self):
        raise NotImplementedError
 class _ProactorSocketTransport(_ProactorReadPipeTransport,
                               _ProactorBaseWritePipeTransport,
                               transports.Transport):
    """Transport for connected sockets."""
    _sendfile_compatible = constants._SendfileMode.TRY_NATIVE
    def __init__(self, loop, sock, protocol, waiter=None,
                 extra=None, server=None):
        super().__init__(loop, sock, protocol, waiter, extra, server)
        base_events._set_nodelay(sock)
    def _set_extra(self, sock):
        self._extra['socket'] = sock
        try:
            self._extra['sockname'] = sock.getsockname()
        except (socket.error, AttributeError):
            if self._loop.get_debug():
                logger.warning(
                    "getsockname() failed on %r", sock, exc_info=True)
        if 'peername' not in self._extra:
            try:
                self._extra['peername'] = sock.getpeername()
            except (socket.error, AttributeError):
                if self._loop.get_debug():
                    logger.warning("getpeername() failed on %r",
                                   sock, exc_info=True)
    def can_write_eof(self):
        return True
    def write_eof(self):
        if self._closing or self._eof_written:
            return
        self._eof_written = True
        if self._write_fut is None:
            self._sock.shutdown(socket.SHUT_WR)
 class BaseProactorEventLoop(base_events.BaseEventLoop):
    def __init__(self, proactor):
        super().__init__()
        logger.debug('Using proactor: %s', proactor.__class__.__name__)
        self._proactor = proactor
        self._selector = proactor   # convenient alias
        self._self_reading_future = None
        self._accept_futures = {}   # socket file descriptor => Future
        proactor.set_loop(self)
        self._make_self_pipe()
    def _make_socket_transport(self, sock, protocol, waiter=None,
                               extra=None, server=None):
        return _ProactorSocketTransport(self, sock, protocol, waiter,
                                        extra, server)
    def _make_ssl_transport(
            self, rawsock, protocol, sslcontext, waiter=None,
            *, server_side=False, server_hostname=None,
            extra=None, server=None,
            ssl_handshake_timeout=None):
        ssl_protocol = sslproto.SSLProtocol(
                self, protocol, sslcontext, waiter,
                server_side, server_hostname,
                ssl_handshake_timeout=ssl_handshake_timeout)
        _ProactorSocketTransport(self, rawsock, ssl_protocol,
                                 extra=extra, server=server)
        return ssl_protocol._app_transport
    def _make_duplex_pipe_transport(self, sock, protocol, waiter=None,
                                    extra=None):
        return _ProactorDuplexPipeTransport(self,
                                            sock, protocol, waiter, extra)
    def _make_read_pipe_transport(self, sock, protocol, waiter=None,
                                  extra=None):
        return _ProactorReadPipeTransport(self, sock, protocol, waiter, extra)
    def _make_write_pipe_transport(self, sock, protocol, waiter=None,
                                   extra=None):
        # We want connection_lost() to be called when other end closes
        return _ProactorWritePipeTransport(self,
                                           sock, protocol, waiter, extra)
    def close(self):
        if self.is_running():
            raise RuntimeError("Cannot close a running event loop")
        if self.is_closed():
            return
        # Call these methods before closing the event loop (before calling
        # BaseEventLoop.close), because they can schedule callbacks with
        # call_soon(), which is forbidden when the event loop is closed.
        self._stop_accept_futures()
        self._close_self_pipe()
        self._proactor.close()
        self._proactor = None
        self._selector = None
        # Close the event loop
        super().close()
    async def sock_recv(self, sock, n):
        return await self._proactor.recv(sock, n)
    async def sock_recv_into(self, sock, buf):
        return await self._proactor.recv_into(sock, buf)
    async def sock_sendall(self, sock, data):
        return await self._proactor.send(sock, data)
    async def sock_connect(self, sock, address):
        return await self._proactor.connect(sock, address)
    async def sock_accept(self, sock):
        return await self._proactor.accept(sock)
    async def _sock_sendfile_native(self, sock, file, offset, count):
        try:
            fileno = file.fileno()
        except (AttributeError, io.UnsupportedOperation) as err:
            raise events.SendfileNotAvailableError("not a regular file")
        try:
            fsize = os.fstat(fileno).st_size
        except OSError as err:
            raise events.SendfileNotAvailableError("not a regular file")
        blocksize = count if count else fsize
        if not blocksize:
            return 0  # empty file
        blocksize = min(blocksize, 0xffff_ffff)
        end_pos = min(offset + count, fsize) if count else fsize
        offset = min(offset, fsize)
        total_sent = 0
        try:
            while True:
                blocksize = min(end_pos - offset, blocksize)
                if blocksize <= 0:
                    return total_sent
                await self._proactor.sendfile(sock, file, offset, blocksize)
                offset += blocksize
                total_sent += blocksize
        finally:
            if total_sent > 0:
                file.seek(offset)
    async def _sendfile_native(self, transp, file, offset, count):
        resume_reading = transp.is_reading()
        transp.pause_reading()
        await transp._make_empty_waiter()
        try:
            return await self.sock_sendfile(transp._sock, file, offset, count,
                                            fallback=False)
        finally:
            transp._reset_empty_waiter()
            if resume_reading:
                transp.resume_reading()
    def _close_self_pipe(self):
        if self._self_reading_future is not None:
            self._self_reading_future.cancel()
            self._self_reading_future = None
        self._ssock.close()
        self._ssock = None
        self._csock.close()
        self._csock = None
        self._internal_fds -= 1
    def _make_self_pipe(self):
        # A self-socket, really. :-)
        self._ssock, self._csock = socket.socketpair()
        self._ssock.setblocking(False)
        self._csock.setblocking(False)
        self._internal_fds += 1
        self.call_soon(self._loop_self_reading)
    def _loop_self_reading(self, f=None):
        try:
            if f is not None:
                f.result()  # may raise
            f = self._proactor.recv(self._ssock, 4096)
        except futures.CancelledError:
            # _close_self_pipe() has been called, stop waiting for data
            return
        except Exception as exc:
            self.call_exception_handler({
                'message': 'Error on reading from the event loop self pipe',
                'exception': exc,
                'loop': self,
            })
        else:
            self._self_reading_future = f
            f.add_done_callback(self._loop_self_reading)
    def _write_to_self(self):
        self._csock.send(b'\0')
    def _start_serving(self, protocol_factory, sock,
                       sslcontext=None, server=None, backlog=100,
                       ssl_handshake_timeout=None):
        def loop(f=None):
            try:
                if f is not None:
                    conn, addr = f.result()
                    if self._debug:
                        logger.debug("%r got a new connection from %r: %r",
                                     server, addr, conn)
                    protocol = protocol_factory()
                    if sslcontext is not None:
                        self._make_ssl_transport(
                            conn, protocol, sslcontext, server_side=True,
                            extra={'peername': addr}, server=server,
                            ssl_handshake_timeout=ssl_handshake_timeout)
                    else:
                        self._make_socket_transport(
                            conn, protocol,
                            extra={'peername': addr}, server=server)
                if self.is_closed():
                    return
                f = self._proactor.accept(sock)
            except OSError as exc:
                if sock.fileno() != -1:
                    self.call_exception_handler({
                        'message': 'Accept failed on a socket',
                        'exception': exc,
                        'socket': sock,
                    })
                    sock.close()
                elif self._debug:
                    logger.debug("Accept failed on socket %r",
                                 sock, exc_info=True)
            except futures.CancelledError:
                sock.close()
            else:
                self._accept_futures[sock.fileno()] = f
                f.add_done_callback(loop)
        self.call_soon(loop)
    def _process_events(self, event_list):
        # Events are processed in the IocpProactor._poll() method
        pass
    def _stop_accept_futures(self):
        for future in self._accept_futures.values():
            future.cancel()
        self._accept_futures.clear()
    def _stop_serving(self, sock):
        future = self._accept_futures.pop(sock.fileno(), None)
        if future:
            future.cancel()
        self._proactor._stop_serving(sock)
        sock.close()
--- a/Lib/asyncio/protocols.py
+++ b/Lib/asyncio/protocols.py
@ -0,0 +1,210 @@
 """Abstract Protocol base classes."""
 __all__ = (
    'BaseProtocol', 'Protocol', 'DatagramProtocol',
    'SubprocessProtocol', 'BufferedProtocol',
 )
 class BaseProtocol:
    """Common base class for protocol interfaces.
    Usually user implements protocols that derived from BaseProtocol
    like Protocol or ProcessProtocol.
    The only case when BaseProtocol should be implemented directly is
    write-only transport like write pipe
    """
    def connection_made(self, transport):
        """Called when a connection is made.
        The argument is the transport representing the pipe connection.
        To receive data, wait for data_received() calls.
        When the connection is closed, connection_lost() is called.
        """
    def connection_lost(self, exc):
        """Called when the connection is lost or closed.
        The argument is an exception object or None (the latter
        meaning a regular EOF is received or the connection was
        aborted or closed).
        """
    def pause_writing(self):
        """Called when the transport's buffer goes over the high-water mark.
        Pause and resume calls are paired -- pause_writing() is called
        once when the buffer goes strictly over the high-water mark
        (even if subsequent writes increases the buffer size even
        more), and eventually resume_writing() is called once when the
        buffer size reaches the low-water mark.
        Note that if the buffer size equals the high-water mark,
        pause_writing() is not called -- it must go strictly over.
        Conversely, resume_writing() is called when the buffer size is
        equal or lower than the low-water mark.  These end conditions
        are important to ensure that things go as expected when either
        mark is zero.
        NOTE: This is the only Protocol callback that is not called
        through EventLoop.call_soon() -- if it were, it would have no
        effect when it's most needed (when the app keeps writing
        without yielding until pause_writing() is called).
        """
    def resume_writing(self):
        """Called when the transport's buffer drains below the low-water mark.
        See pause_writing() for details.
        """
 class Protocol(BaseProtocol):
    """Interface for stream protocol.
    The user should implement this interface.  They can inherit from
    this class but don't need to.  The implementations here do
    nothing (they don't raise exceptions).
    When the user wants to requests a transport, they pass a protocol
    factory to a utility function (e.g., EventLoop.create_connection()).
    When the connection is made successfully, connection_made() is
    called with a suitable transport object.  Then data_received()
    will be called 0 or more times with data (bytes) received from the
    transport; finally, connection_lost() will be called exactly once
    with either an exception object or None as an argument.
    State machine of calls:
      start -> CM [-> DR*] [-> ER?] -> CL -> end
    * CM: connection_made()
    * DR: data_received()
    * ER: eof_received()
    * CL: connection_lost()
    """
    def data_received(self, data):
        """Called when some data is received.
        The argument is a bytes object.
        """
    def eof_received(self):
        """Called when the other end calls write_eof() or equivalent.
        If this returns a false value (including None), the transport
        will close itself.  If it returns a true value, closing the
        transport is up to the protocol.
        """
 class BufferedProtocol(BaseProtocol):
    """Interface for stream protocol with manual buffer control.
    Important: this has been added to asyncio in Python 3.7
    *on a provisional basis*!  Consider it as an experimental API that
    might be changed or removed in Python 3.8.
    Event methods, such as `create_server` and `create_connection`,
    accept factories that return protocols that implement this interface.
    The idea of BufferedProtocol is that it allows to manually allocate
    and control the receive buffer.  Event loops can then use the buffer
    provided by the protocol to avoid unnecessary data copies.  This
    can result in noticeable performance improvement for protocols that
    receive big amounts of data.  Sophisticated protocols can allocate
    the buffer only once at creation time.
    State machine of calls:
      start -> CM [-> GB [-> BU?]]* [-> ER?] -> CL -> end
    * CM: connection_made()
    * GB: get_buffer()
    * BU: buffer_updated()
    * ER: eof_received()
    * CL: connection_lost()
    """
    def get_buffer(self, sizehint):
        """Called to allocate a new receive buffer.
        *sizehint* is a recommended minimal size for the returned
        buffer.  When set to -1, the buffer size can be arbitrary.
        Must return an object that implements the
        :ref:`buffer protocol <bufferobjects>`.
        It is an error to return a zero-sized buffer.
        """
    def buffer_updated(self, nbytes):
        """Called when the buffer was updated with the received data.
        *nbytes* is the total number of bytes that were written to
        the buffer.
        """
    def eof_received(self):
        """Called when the other end calls write_eof() or equivalent.
        If this returns a false value (including None), the transport
        will close itself.  If it returns a true value, closing the
        transport is up to the protocol.
        """
 class DatagramProtocol(BaseProtocol):
    """Interface for datagram protocol."""
    def datagram_received(self, data, addr):
        """Called when some datagram is received."""
    def error_received(self, exc):
        """Called when a send or receive operation raises an OSError.
        (Other than BlockingIOError or InterruptedError.)
        """
 class SubprocessProtocol(BaseProtocol):
    """Interface for protocol for subprocess calls."""
    def pipe_data_received(self, fd, data):
        """Called when the subprocess writes data into stdout/stderr pipe.
        fd is int file descriptor.
        data is bytes object.
        """
    def pipe_connection_lost(self, fd, exc):
        """Called when a file descriptor associated with the child process is
        closed.
        fd is the int file descriptor that was closed.
        """
    def process_exited(self):
        """Called when subprocess has exited."""
 def _feed_data_to_buffered_proto(proto, data):
    data_len = len(data)
    while data_len:
        buf = proto.get_buffer(data_len)
        buf_len = len(buf)
        if not buf_len:
            raise RuntimeError('get_buffer() returned an empty buffer')
        if buf_len >= data_len:
            buf[:data_len] = data
            proto.buffer_updated(data_len)
            return
        else:
            buf[:buf_len] = data[:buf_len]
            proto.buffer_updated(buf_len)
            data = data[buf_len:]
            data_len = len(data)
--- a/Lib/asyncio/queues.py
+++ b/Lib/asyncio/queues.py
@ -0,0 +1,245 @@
 __all__ = ('Queue', 'PriorityQueue', 'LifoQueue', 'QueueFull', 'QueueEmpty')
 import collections
 import heapq
 from . import events
 from . import locks
 class QueueEmpty(Exception):
    """Raised when Queue.get_nowait() is called on an empty Queue."""
    pass
 class QueueFull(Exception):
    """Raised when the Queue.put_nowait() method is called on a full Queue."""
    pass
 class Queue:
    """A queue, useful for coordinating producer and consumer coroutines.
    If maxsize is less than or equal to zero, the queue size is infinite. If it
    is an integer greater than 0, then "await put()" will block when the
    queue reaches maxsize, until an item is removed by get().
    Unlike the standard library Queue, you can reliably know this Queue's size
    with qsize(), since your single-threaded asyncio application won't be
    interrupted between calling qsize() and doing an operation on the Queue.
    """
    def __init__(self, maxsize=0, *, loop=None):
        if loop is None:
            self._loop = events.get_event_loop()
        else:
            self._loop = loop
        self._maxsize = maxsize
        # Futures.
        self._getters = collections.deque()
        # Futures.
        self._putters = collections.deque()
        self._unfinished_tasks = 0
        self._finished = locks.Event(loop=self._loop)
        self._finished.set()
        self._init(maxsize)
    # These three are overridable in subclasses.
    def _init(self, maxsize):
        self._queue = collections.deque()
    def _get(self):
        return self._queue.popleft()
    def _put(self, item):
        self._queue.append(item)
    # End of the overridable methods.
    def _wakeup_next(self, waiters):
        # Wake up the next waiter (if any) that isn't cancelled.
        while waiters:
            waiter = waiters.popleft()
            if not waiter.done():
                waiter.set_result(None)
                break
    def __repr__(self):
        return f'<{type(self).__name__} at {id(self):#x} {self._format()}>'
    def __str__(self):
        return f'<{type(self).__name__} {self._format()}>'
    def _format(self):
        result = f'maxsize={self._maxsize!r}'
        if getattr(self, '_queue', None):
            result += f' _queue={list(self._queue)!r}'
        if self._getters:
            result += f' _getters[{len(self._getters)}]'
        if self._putters:
            result += f' _putters[{len(self._putters)}]'
        if self._unfinished_tasks:
            result += f' tasks={self._unfinished_tasks}'
        return result
    def qsize(self):
        """Number of items in the queue."""
        return len(self._queue)
    @property
    def maxsize(self):
        """Number of items allowed in the queue."""
        return self._maxsize
    def empty(self):
        """Return True if the queue is empty, False otherwise."""
        return not self._queue
    def full(self):
        """Return True if there are maxsize items in the queue.
        Note: if the Queue was initialized with maxsize=0 (the default),
        then full() is never True.
        """
        if self._maxsize <= 0:
            return False
        else:
            return self.qsize() >= self._maxsize
    async def put(self, item):
        """Put an item into the queue.
        Put an item into the queue. If the queue is full, wait until a free
        slot is available before adding item.
        """
        while self.full():
            putter = self._loop.create_future()
            self._putters.append(putter)
            try:
                await putter
            except:
                putter.cancel()  # Just in case putter is not done yet.
                try:
                    # Clean self._putters from canceled putters.
                    self._putters.remove(putter)
                except ValueError:
                    # The putter could be removed from self._putters by a
                    # previous get_nowait call.
                    pass
                if not self.full() and not putter.cancelled():
                    # We were woken up by get_nowait(), but can't take
                    # the call.  Wake up the next in line.
                    self._wakeup_next(self._putters)
                raise
        return self.put_nowait(item)
    def put_nowait(self, item):
        """Put an item into the queue without blocking.
        If no free slot is immediately available, raise QueueFull.
        """
        if self.full():
            raise QueueFull
        self._put(item)
        self._unfinished_tasks += 1
        self._finished.clear()
        self._wakeup_next(self._getters)
    async def get(self):
        """Remove and return an item from the queue.
        If queue is empty, wait until an item is available.
        """
        while self.empty():
            getter = self._loop.create_future()
            self._getters.append(getter)
            try:
                await getter
            except:
                getter.cancel()  # Just in case getter is not done yet.
                try:
                    # Clean self._getters from canceled getters.
                    self._getters.remove(getter)
                except ValueError:
                    # The getter could be removed from self._getters by a
                    # previous put_nowait call.
                    pass
                if not self.empty() and not getter.cancelled():
                    # We were woken up by put_nowait(), but can't take
                    # the call.  Wake up the next in line.
                    self._wakeup_next(self._getters)
                raise
        return self.get_nowait()
    def get_nowait(self):
        """Remove and return an item from the queue.
        Return an item if one is immediately available, else raise QueueEmpty.
        """
        if self.empty():
            raise QueueEmpty
        item = self._get()
        self._wakeup_next(self._putters)
        return item
    def task_done(self):
        """Indicate that a formerly enqueued task is complete.
        Used by queue consumers. For each get() used to fetch a task,
        a subsequent call to task_done() tells the queue that the processing
        on the task is complete.
        If a join() is currently blocking, it will resume when all items have
        been processed (meaning that a task_done() call was received for every
        item that had been put() into the queue).
        Raises ValueError if called more times than there were items placed in
        the queue.
        """
        if self._unfinished_tasks <= 0:
            raise ValueError('task_done() called too many times')
        self._unfinished_tasks -= 1
        if self._unfinished_tasks == 0:
            self._finished.set()
    async def join(self):
        """Block until all items in the queue have been gotten and processed.
        The count of unfinished tasks goes up whenever an item is added to the
        queue. The count goes down whenever a consumer calls task_done() to
        indicate that the item was retrieved and all work on it is complete.
        When the count of unfinished tasks drops to zero, join() unblocks.
        """
        if self._unfinished_tasks > 0:
            await self._finished.wait()
 class PriorityQueue(Queue):
    """A subclass of Queue; retrieves entries in priority order (lowest first).
    Entries are typically tuples of the form: (priority number, data).
    """
    def _init(self, maxsize):
        self._queue = []
    def _put(self, item, heappush=heapq.heappush):
        heappush(self._queue, item)
    def _get(self, heappop=heapq.heappop):
        return heappop(self._queue)
 class LifoQueue(Queue):
    """A subclass of Queue that retrieves most recently added entries first."""
    def _init(self, maxsize):
        self._queue = []
    def _put(self, item):
        self._queue.append(item)
    def _get(self):
        return self._queue.pop()
--- a/Lib/asyncio/runners.py
+++ b/Lib/asyncio/runners.py
@ -0,0 +1,72 @@
 __all__ = 'run',
 from . import coroutines
 from . import events
 from . import tasks
 def run(main, *, debug=False):
    """Run a coroutine.
    This function runs the passed coroutine, taking care of
    managing the asyncio event loop and finalizing asynchronous
    generators.
    This function cannot be called when another asyncio event loop is
    running in the same thread.
    If debug is True, the event loop will be run in debug mode.
    This function always creates a new event loop and closes it at the end.
    It should be used as a main entry point for asyncio programs, and should
    ideally only be called once.
    Example:
        async def main():
            await asyncio.sleep(1)
            print('hello')
        asyncio.run(main())
    """
    if events._get_running_loop() is not None:
        raise RuntimeError(
            "asyncio.run() cannot be called from a running event loop")
    if not coroutines.iscoroutine(main):
        raise ValueError("a coroutine was expected, got {!r}".format(main))
    loop = events.new_event_loop()
    try:
        events.set_event_loop(loop)
        loop.set_debug(debug)
        return loop.run_until_complete(main)
    finally:
        try:
            _cancel_all_tasks(loop)
            loop.run_until_complete(loop.shutdown_asyncgens())
        finally:
            events.set_event_loop(None)
            loop.close()
 def _cancel_all_tasks(loop):
    to_cancel = tasks.all_tasks(loop)
    if not to_cancel:
        return
    for task in to_cancel:
        task.cancel()
    loop.run_until_complete(
        tasks.gather(*to_cancel, loop=loop, return_exceptions=True))
    for task in to_cancel:
        if task.cancelled():
            continue
        if task.exception() is not None:
            loop.call_exception_handler({
                'message': 'unhandled exception during asyncio.run() shutdown',
                'exception': task.exception(),
                'task': task,
            })
--- a/Lib/asyncio/selector_events.py
+++ b/Lib/asyncio/selector_events.py
--- a/Lib/asyncio/sslproto.py
+++ b/Lib/asyncio/sslproto.py
@ -0,0 +1,723 @@
 import collections
 import warnings
 try:
    import ssl
 except ImportError:  # pragma: no cover
    ssl = None
 from . import base_events
 from . import constants
 from . import protocols
 from . import transports
 from .log import logger
 def _create_transport_context(server_side, server_hostname):
    if server_side:
        raise ValueError('Server side SSL needs a valid SSLContext')
    # Client side may pass ssl=True to use a default
    # context; in that case the sslcontext passed is None.
    # The default is secure for client connections.
    # Python 3.4+: use up-to-date strong settings.
    sslcontext = ssl.create_default_context()
    if not server_hostname:
        sslcontext.check_hostname = False
    return sslcontext
 # States of an _SSLPipe.
 _UNWRAPPED = "UNWRAPPED"
 _DO_HANDSHAKE = "DO_HANDSHAKE"
 _WRAPPED = "WRAPPED"
 _SHUTDOWN = "SHUTDOWN"
 class _SSLPipe(object):
    """An SSL "Pipe".
    An SSL pipe allows you to communicate with an SSL/TLS protocol instance
    through memory buffers. It can be used to implement a security layer for an
    existing connection where you don't have access to the connection's file
    descriptor, or for some reason you don't want to use it.
    An SSL pipe can be in "wrapped" and "unwrapped" mode. In unwrapped mode,
    data is passed through untransformed. In wrapped mode, application level
    data is encrypted to SSL record level data and vice versa. The SSL record
    level is the lowest level in the SSL protocol suite and is what travels
    as-is over the wire.
    An SslPipe initially is in "unwrapped" mode. To start SSL, call
    do_handshake(). To shutdown SSL again, call unwrap().
    """
    max_size = 256 * 1024   # Buffer size passed to read()
    def __init__(self, context, server_side, server_hostname=None):
        """
        The *context* argument specifies the ssl.SSLContext to use.
        The *server_side* argument indicates whether this is a server side or
        client side transport.
        The optional *server_hostname* argument can be used to specify the
        hostname you are connecting to. You may only specify this parameter if
        the _ssl module supports Server Name Indication (SNI).
        """
        self._context = context
        self._server_side = server_side
        self._server_hostname = server_hostname
        self._state = _UNWRAPPED
        self._incoming = ssl.MemoryBIO()
        self._outgoing = ssl.MemoryBIO()
        self._sslobj = None
        self._need_ssldata = False
        self._handshake_cb = None
        self._shutdown_cb = None
    @property
    def context(self):
        """The SSL context passed to the constructor."""
        return self._context
    @property
    def ssl_object(self):
        """The internal ssl.SSLObject instance.
        Return None if the pipe is not wrapped.
        """
        return self._sslobj
    @property
    def need_ssldata(self):
        """Whether more record level data is needed to complete a handshake
        that is currently in progress."""
        return self._need_ssldata
    @property
    def wrapped(self):
        """
        Whether a security layer is currently in effect.
        Return False during handshake.
        """
        return self._state == _WRAPPED
    def do_handshake(self, callback=None):
        """Start the SSL handshake.
        Return a list of ssldata. A ssldata element is a list of buffers
        The optional *callback* argument can be used to install a callback that
        will be called when the handshake is complete. The callback will be
        called with None if successful, else an exception instance.
        """
        if self._state != _UNWRAPPED:
            raise RuntimeError('handshake in progress or completed')
        self._sslobj = self._context.wrap_bio(
            self._incoming, self._outgoing,
            server_side=self._server_side,
            server_hostname=self._server_hostname)
        self._state = _DO_HANDSHAKE
        self._handshake_cb = callback
        ssldata, appdata = self.feed_ssldata(b'', only_handshake=True)
        assert len(appdata) == 0
        return ssldata
    def shutdown(self, callback=None):
        """Start the SSL shutdown sequence.
        Return a list of ssldata. A ssldata element is a list of buffers
        The optional *callback* argument can be used to install a callback that
        will be called when the shutdown is complete. The callback will be
        called without arguments.
        """
        if self._state == _UNWRAPPED:
            raise RuntimeError('no security layer present')
        if self._state == _SHUTDOWN:
            raise RuntimeError('shutdown in progress')
        assert self._state in (_WRAPPED, _DO_HANDSHAKE)
        self._state = _SHUTDOWN
        self._shutdown_cb = callback
        ssldata, appdata = self.feed_ssldata(b'')
        assert appdata == [] or appdata == [b'']
        return ssldata
    def feed_eof(self):
        """Send a potentially "ragged" EOF.
        This method will raise an SSL_ERROR_EOF exception if the EOF is
        unexpected.
        """
        self._incoming.write_eof()
        ssldata, appdata = self.feed_ssldata(b'')
        assert appdata == [] or appdata == [b'']
    def feed_ssldata(self, data, only_handshake=False):
        """Feed SSL record level data into the pipe.
        The data must be a bytes instance. It is OK to send an empty bytes
        instance. This can be used to get ssldata for a handshake initiated by
        this endpoint.
        Return a (ssldata, appdata) tuple. The ssldata element is a list of
        buffers containing SSL data that needs to be sent to the remote SSL.
        The appdata element is a list of buffers containing plaintext data that
        needs to be forwarded to the application. The appdata list may contain
        an empty buffer indicating an SSL "close_notify" alert. This alert must
        be acknowledged by calling shutdown().
        """
        if self._state == _UNWRAPPED:
            # If unwrapped, pass plaintext data straight through.
            if data:
                appdata = [data]
            else:
                appdata = []
            return ([], appdata)
        self._need_ssldata = False
        if data:
            self._incoming.write(data)
        ssldata = []
        appdata = []
        try:
            if self._state == _DO_HANDSHAKE:
                # Call do_handshake() until it doesn't raise anymore.
                self._sslobj.do_handshake()
                self._state = _WRAPPED
                if self._handshake_cb:
                    self._handshake_cb(None)
                if only_handshake:
                    return (ssldata, appdata)
                # Handshake done: execute the wrapped block
            if self._state == _WRAPPED:
                # Main state: read data from SSL until close_notify
                while True:
                    chunk = self._sslobj.read(self.max_size)
                    appdata.append(chunk)
                    if not chunk:  # close_notify
                        break
            elif self._state == _SHUTDOWN:
                # Call shutdown() until it doesn't raise anymore.
                self._sslobj.unwrap()
                self._sslobj = None
                self._state = _UNWRAPPED
                if self._shutdown_cb:
                    self._shutdown_cb()
            elif self._state == _UNWRAPPED:
                # Drain possible plaintext data after close_notify.
                appdata.append(self._incoming.read())
        except (ssl.SSLError, ssl.CertificateError) as exc:
            exc_errno = getattr(exc, 'errno', None)
            if exc_errno not in (
                    ssl.SSL_ERROR_WANT_READ, ssl.SSL_ERROR_WANT_WRITE,
                    ssl.SSL_ERROR_SYSCALL):
                if self._state == _DO_HANDSHAKE and self._handshake_cb:
                    self._handshake_cb(exc)
                raise
            self._need_ssldata = (exc_errno == ssl.SSL_ERROR_WANT_READ)
        # Check for record level data that needs to be sent back.
        # Happens for the initial handshake and renegotiations.
        if self._outgoing.pending:
            ssldata.append(self._outgoing.read())
        return (ssldata, appdata)
    def feed_appdata(self, data, offset=0):
        """Feed plaintext data into the pipe.
        Return an (ssldata, offset) tuple. The ssldata element is a list of
        buffers containing record level data that needs to be sent to the
        remote SSL instance. The offset is the number of plaintext bytes that
        were processed, which may be less than the length of data.
        NOTE: In case of short writes, this call MUST be retried with the SAME
        buffer passed into the *data* argument (i.e. the id() must be the
        same). This is an OpenSSL requirement. A further particularity is that
        a short write will always have offset == 0, because the _ssl module
        does not enable partial writes. And even though the offset is zero,
        there will still be encrypted data in ssldata.
        """
        assert 0 <= offset <= len(data)
        if self._state == _UNWRAPPED:
            # pass through data in unwrapped mode
            if offset < len(data):
                ssldata = [data[offset:]]
            else:
                ssldata = []
            return (ssldata, len(data))
        ssldata = []
        view = memoryview(data)
        while True:
            self._need_ssldata = False
            try:
                if offset < len(view):
                    offset += self._sslobj.write(view[offset:])
            except ssl.SSLError as exc:
                # It is not allowed to call write() after unwrap() until the
                # close_notify is acknowledged. We return the condition to the
                # caller as a short write.
                exc_errno = getattr(exc, 'errno', None)
                if exc.reason == 'PROTOCOL_IS_SHUTDOWN':
                    exc_errno = exc.errno = ssl.SSL_ERROR_WANT_READ
                if exc_errno not in (ssl.SSL_ERROR_WANT_READ,
                                     ssl.SSL_ERROR_WANT_WRITE,
                                     ssl.SSL_ERROR_SYSCALL):
                    raise
                self._need_ssldata = (exc_errno == ssl.SSL_ERROR_WANT_READ)
            # See if there's any record level data back for us.
            if self._outgoing.pending:
                ssldata.append(self._outgoing.read())
            if offset == len(view) or self._need_ssldata:
                break
        return (ssldata, offset)
 class _SSLProtocolTransport(transports._FlowControlMixin,
                            transports.Transport):
    _sendfile_compatible = constants._SendfileMode.FALLBACK
    def __init__(self, loop, ssl_protocol):
        self._loop = loop
        # SSLProtocol instance
        self._ssl_protocol = ssl_protocol
        self._closed = False
    def get_extra_info(self, name, default=None):
        """Get optional transport information."""
        return self._ssl_protocol._get_extra_info(name, default)
    def set_protocol(self, protocol):
        self._ssl_protocol._set_app_protocol(protocol)
    def get_protocol(self):
        return self._ssl_protocol._app_protocol
    def is_closing(self):
        return self._closed
    def close(self):
        """Close the transport.
        Buffered data will be flushed asynchronously.  No more data
        will be received.  After all buffered data is flushed, the
        protocol's connection_lost() method will (eventually) called
        with None as its argument.
        """
        self._closed = True
        self._ssl_protocol._start_shutdown()
    def __del__(self):
        if not self._closed:
            warnings.warn(f"unclosed transport {self!r}", ResourceWarning,
                          source=self)
            self.close()
    def is_reading(self):
        tr = self._ssl_protocol._transport
        if tr is None:
            raise RuntimeError('SSL transport has not been initialized yet')
        return tr.is_reading()
    def pause_reading(self):
        """Pause the receiving end.
        No data will be passed to the protocol's data_received()
        method until resume_reading() is called.
        """
        self._ssl_protocol._transport.pause_reading()
    def resume_reading(self):
        """Resume the receiving end.
        Data received will once again be passed to the protocol's
        data_received() method.
        """
        self._ssl_protocol._transport.resume_reading()
    def set_write_buffer_limits(self, high=None, low=None):
        """Set the high- and low-water limits for write flow control.
        These two values control when to call the protocol's
        pause_writing() and resume_writing() methods.  If specified,
        the low-water limit must be less than or equal to the
        high-water limit.  Neither value can be negative.
        The defaults are implementation-specific.  If only the
        high-water limit is given, the low-water limit defaults to an
        implementation-specific value less than or equal to the
        high-water limit.  Setting high to zero forces low to zero as
        well, and causes pause_writing() to be called whenever the
        buffer becomes non-empty.  Setting low to zero causes
        resume_writing() to be called only once the buffer is empty.
        Use of zero for either limit is generally sub-optimal as it
        reduces opportunities for doing I/O and computation
        concurrently.
        """
        self._ssl_protocol._transport.set_write_buffer_limits(high, low)
    def get_write_buffer_size(self):
        """Return the current size of the write buffer."""
        return self._ssl_protocol._transport.get_write_buffer_size()
    @property
    def _protocol_paused(self):
        # Required for sendfile fallback pause_writing/resume_writing logic
        return self._ssl_protocol._transport._protocol_paused
    def write(self, data):
        """Write some data bytes to the transport.
        This does not block; it buffers the data and arranges for it
        to be sent out asynchronously.
        """
        if not isinstance(data, (bytes, bytearray, memoryview)):
            raise TypeError(f"data: expecting a bytes-like instance, "
                            f"got {type(data).__name__}")
        if not data:
            return
        self._ssl_protocol._write_appdata(data)
    def can_write_eof(self):
        """Return True if this transport supports write_eof(), False if not."""
        return False
    def abort(self):
        """Close the transport immediately.
        Buffered data will be lost.  No more data will be received.
        The protocol's connection_lost() method will (eventually) be
        called with None as its argument.
        """
        self._ssl_protocol._abort()
        self._closed = True
 class SSLProtocol(protocols.Protocol):
    """SSL protocol.
    Implementation of SSL on top of a socket using incoming and outgoing
    buffers which are ssl.MemoryBIO objects.
    """
    def __init__(self, loop, app_protocol, sslcontext, waiter,
                 server_side=False, server_hostname=None,
                 call_connection_made=True,
                 ssl_handshake_timeout=None):
        if ssl is None:
            raise RuntimeError('stdlib ssl module not available')
        if ssl_handshake_timeout is None:
            ssl_handshake_timeout = constants.SSL_HANDSHAKE_TIMEOUT
        elif ssl_handshake_timeout <= 0:
            raise ValueError(
                f"ssl_handshake_timeout should be a positive number, "
                f"got {ssl_handshake_timeout}")
        if not sslcontext:
            sslcontext = _create_transport_context(
                server_side, server_hostname)
        self._server_side = server_side
        if server_hostname and not server_side:
            self._server_hostname = server_hostname
        else:
            self._server_hostname = None
        self._sslcontext = sslcontext
        # SSL-specific extra info. More info are set when the handshake
        # completes.
        self._extra = dict(sslcontext=sslcontext)
        # App data write buffering
        self._write_backlog = collections.deque()
        self._write_buffer_size = 0
        self._waiter = waiter
        self._loop = loop
        self._set_app_protocol(app_protocol)
        self._app_transport = _SSLProtocolTransport(self._loop, self)
        # _SSLPipe instance (None until the connection is made)
        self._sslpipe = None
        self._session_established = False
        self._in_handshake = False
        self._in_shutdown = False
        # transport, ex: SelectorSocketTransport
        self._transport = None
        self._call_connection_made = call_connection_made
        self._ssl_handshake_timeout = ssl_handshake_timeout
    def _set_app_protocol(self, app_protocol):
        self._app_protocol = app_protocol
        self._app_protocol_is_buffer = \
            isinstance(app_protocol, protocols.BufferedProtocol)
    def _wakeup_waiter(self, exc=None):
        if self._waiter is None:
            return
        if not self._waiter.cancelled():
            if exc is not None:
                self._waiter.set_exception(exc)
            else:
                self._waiter.set_result(None)
        self._waiter = None
    def connection_made(self, transport):
        """Called when the low-level connection is made.
        Start the SSL handshake.
        """
        self._transport = transport
        self._sslpipe = _SSLPipe(self._sslcontext,
                                 self._server_side,
                                 self._server_hostname)
        self._start_handshake()
    def connection_lost(self, exc):
        """Called when the low-level connection is lost or closed.
        The argument is an exception object or None (the latter
        meaning a regular EOF is received or the connection was
        aborted or closed).
        """
        if self._session_established:
            self._session_established = False
            self._loop.call_soon(self._app_protocol.connection_lost, exc)
        else:
            # Most likely an exception occurred while in SSL handshake.
            # Just mark the app transport as closed so that its __del__
            # doesn't complain.
            if self._app_transport is not None:
                self._app_transport._closed = True
        self._transport = None
        self._app_transport = None
        self._wakeup_waiter(exc)
    def pause_writing(self):
        """Called when the low-level transport's buffer goes over
        the high-water mark.
        """
        self._app_protocol.pause_writing()
    def resume_writing(self):
        """Called when the low-level transport's buffer drains below
        the low-water mark.
        """
        self._app_protocol.resume_writing()
    def data_received(self, data):
        """Called when some SSL data is received.
        The argument is a bytes object.
        """
        if self._sslpipe is None:
            # transport closing, sslpipe is destroyed
            return
        try:
            ssldata, appdata = self._sslpipe.feed_ssldata(data)
        except Exception as e:
            self._fatal_error(e, 'SSL error in data received')
            return
        for chunk in ssldata:
            self._transport.write(chunk)
        for chunk in appdata:
            if chunk:
                try:
                    if self._app_protocol_is_buffer:
                        protocols._feed_data_to_buffered_proto(
                            self._app_protocol, chunk)
                    else:
                        self._app_protocol.data_received(chunk)
                except Exception as ex:
                    self._fatal_error(
                        ex, 'application protocol failed to receive SSL data')
                    return
            else:
                self._start_shutdown()
                break
    def eof_received(self):
        """Called when the other end of the low-level stream
        is half-closed.
        If this returns a false value (including None), the transport
        will close itself.  If it returns a true value, closing the
        transport is up to the protocol.
        """
        try:
            if self._loop.get_debug():
                logger.debug("%r received EOF", self)
            self._wakeup_waiter(ConnectionResetError)
            if not self._in_handshake:
                keep_open = self._app_protocol.eof_received()
                if keep_open:
                    logger.warning('returning true from eof_received() '
                                   'has no effect when using ssl')
        finally:
            self._transport.close()
    def _get_extra_info(self, name, default=None):
        if name in self._extra:
            return self._extra[name]
        elif self._transport is not None:
            return self._transport.get_extra_info(name, default)
        else:
            return default
    def _start_shutdown(self):
        if self._in_shutdown:
            return
        if self._in_handshake:
            self._abort()
        else:
            self._in_shutdown = True
            self._write_appdata(b'')
    def _write_appdata(self, data):
        self._write_backlog.append((data, 0))
        self._write_buffer_size += len(data)
        self._process_write_backlog()
    def _start_handshake(self):
        if self._loop.get_debug():
            logger.debug("%r starts SSL handshake", self)
            self._handshake_start_time = self._loop.time()
        else:
            self._handshake_start_time = None
        self._in_handshake = True
        # (b'', 1) is a special value in _process_write_backlog() to do
        # the SSL handshake
        self._write_backlog.append((b'', 1))
        self._handshake_timeout_handle = \
            self._loop.call_later(self._ssl_handshake_timeout,
                                  self._check_handshake_timeout)
        self._process_write_backlog()
    def _check_handshake_timeout(self):
        if self._in_handshake is True:
            msg = (
                f"SSL handshake is taking longer than "
                f"{self._ssl_handshake_timeout} seconds: "
                f"aborting the connection"
            )
            self._fatal_error(ConnectionAbortedError(msg))
    def _on_handshake_complete(self, handshake_exc):
        self._in_handshake = False
        self._handshake_timeout_handle.cancel()
        sslobj = self._sslpipe.ssl_object
        try:
            if handshake_exc is not None:
                raise handshake_exc
            peercert = sslobj.getpeercert()
        except Exception as exc:
            if isinstance(exc, ssl.CertificateError):
                msg = 'SSL handshake failed on verifying the certificate'
            else:
                msg = 'SSL handshake failed'
            self._fatal_error(exc, msg)
            return
        if self._loop.get_debug():
            dt = self._loop.time() - self._handshake_start_time
            logger.debug("%r: SSL handshake took %.1f ms", self, dt * 1e3)
        # Add extra info that becomes available after handshake.
        self._extra.update(peercert=peercert,
                           cipher=sslobj.cipher(),
                           compression=sslobj.compression(),
                           ssl_object=sslobj,
                           )
        if self._call_connection_made:
            self._app_protocol.connection_made(self._app_transport)
        self._wakeup_waiter()
        self._session_established = True
        # In case transport.write() was already called. Don't call
        # immediately _process_write_backlog(), but schedule it:
        # _on_handshake_complete() can be called indirectly from
        # _process_write_backlog(), and _process_write_backlog() is not
        # reentrant.
        self._loop.call_soon(self._process_write_backlog)
    def _process_write_backlog(self):
        # Try to make progress on the write backlog.
        if self._transport is None or self._sslpipe is None:
            return
        try:
            for i in range(len(self._write_backlog)):
                data, offset = self._write_backlog[0]
                if data:
                    ssldata, offset = self._sslpipe.feed_appdata(data, offset)
                elif offset:
                    ssldata = self._sslpipe.do_handshake(
                        self._on_handshake_complete)
                    offset = 1
                else:
                    ssldata = self._sslpipe.shutdown(self._finalize)
                    offset = 1
                for chunk in ssldata:
                    self._transport.write(chunk)
                if offset < len(data):
                    self._write_backlog[0] = (data, offset)
                    # A short write means that a write is blocked on a read
                    # We need to enable reading if it is paused!
                    assert self._sslpipe.need_ssldata
                    if self._transport._paused:
                        self._transport.resume_reading()
                    break
                # An entire chunk from the backlog was processed. We can
                # delete it and reduce the outstanding buffer size.
                del self._write_backlog[0]
                self._write_buffer_size -= len(data)
        except Exception as exc:
            if self._in_handshake:
                # Exceptions will be re-raised in _on_handshake_complete.
                self._on_handshake_complete(exc)
            else:
                self._fatal_error(exc, 'Fatal error on SSL transport')
    def _fatal_error(self, exc, message='Fatal error on transport'):
        if isinstance(exc, base_events._FATAL_ERROR_IGNORE):
            if self._loop.get_debug():
                logger.debug("%r: %s", self, message, exc_info=True)
        else:
            self._loop.call_exception_handler({
                'message': message,
                'exception': exc,
                'transport': self._transport,
                'protocol': self,
            })
        if self._transport:
            self._transport._force_close(exc)
    def _finalize(self):
        self._sslpipe = None
        if self._transport is not None:
            self._transport.close()
    def _abort(self):
        try:
            if self._transport is not None:
                self._transport.abort()
        finally:
            self._finalize()
--- a/Lib/asyncio/streams.py
+++ b/Lib/asyncio/streams.py
@ -0,0 +1,697 @@
 __all__ = (
    'StreamReader', 'StreamWriter', 'StreamReaderProtocol',
    'open_connection', 'start_server',
    'IncompleteReadError', 'LimitOverrunError',
 )
 import socket
 if hasattr(socket, 'AF_UNIX'):
    __all__ += ('open_unix_connection', 'start_unix_server')
 from . import coroutines
 from . import events
 from . import protocols
 from .log import logger
 from .tasks import sleep
 _DEFAULT_LIMIT = 2 ** 16  # 64 KiB
 class IncompleteReadError(EOFError):
    """
    Incomplete read error. Attributes:
    - partial: read bytes string before the end of stream was reached
    - expected: total number of expected bytes (or None if unknown)
    """
    def __init__(self, partial, expected):
        super().__init__(f'{len(partial)} bytes read on a total of '
                         f'{expected!r} expected bytes')
        self.partial = partial
        self.expected = expected
    def __reduce__(self):
        return type(self), (self.partial, self.expected)
 class LimitOverrunError(Exception):
    """Reached the buffer limit while looking for a separator.
    Attributes:
    - consumed: total number of to be consumed bytes.
    """
    def __init__(self, message, consumed):
        super().__init__(message)
        self.consumed = consumed
    def __reduce__(self):
        return type(self), (self.args[0], self.consumed)
 async def open_connection(host=None, port=None, *,
                          loop=None, limit=_DEFAULT_LIMIT, **kwds):
    """A wrapper for create_connection() returning a (reader, writer) pair.
    The reader returned is a StreamReader instance; the writer is a
    StreamWriter instance.
    The arguments are all the usual arguments to create_connection()
    except protocol_factory; most common are positional host and port,
    with various optional keyword arguments following.
    Additional optional keyword arguments are loop (to set the event loop
    instance to use) and limit (to set the buffer limit passed to the
    StreamReader).
    (If you want to customize the StreamReader and/or
    StreamReaderProtocol classes, just copy the code -- there's
    really nothing special here except some convenience.)
    """
    if loop is None:
        loop = events.get_event_loop()
    reader = StreamReader(limit=limit, loop=loop)
    protocol = StreamReaderProtocol(reader, loop=loop)
    transport, _ = await loop.create_connection(
        lambda: protocol, host, port, **kwds)
    writer = StreamWriter(transport, protocol, reader, loop)
    return reader, writer
 async def start_server(client_connected_cb, host=None, port=None, *,
                       loop=None, limit=_DEFAULT_LIMIT, **kwds):
    """Start a socket server, call back for each client connected.
    The first parameter, `client_connected_cb`, takes two parameters:
    client_reader, client_writer.  client_reader is a StreamReader
    object, while client_writer is a StreamWriter object.  This
    parameter can either be a plain callback function or a coroutine;
    if it is a coroutine, it will be automatically converted into a
    Task.
    The rest of the arguments are all the usual arguments to
    loop.create_server() except protocol_factory; most common are
    positional host and port, with various optional keyword arguments
    following.  The return value is the same as loop.create_server().
    Additional optional keyword arguments are loop (to set the event loop
    instance to use) and limit (to set the buffer limit passed to the
    StreamReader).
    The return value is the same as loop.create_server(), i.e. a
    Server object which can be used to stop the service.
    """
    if loop is None:
        loop = events.get_event_loop()
    def factory():
        reader = StreamReader(limit=limit, loop=loop)
        protocol = StreamReaderProtocol(reader, client_connected_cb,
                                        loop=loop)
        return protocol
    return await loop.create_server(factory, host, port, **kwds)
 if hasattr(socket, 'AF_UNIX'):
    # UNIX Domain Sockets are supported on this platform
    async def open_unix_connection(path=None, *,
                                   loop=None, limit=_DEFAULT_LIMIT, **kwds):
        """Similar to `open_connection` but works with UNIX Domain Sockets."""
        if loop is None:
            loop = events.get_event_loop()
        reader = StreamReader(limit=limit, loop=loop)
        protocol = StreamReaderProtocol(reader, loop=loop)
        transport, _ = await loop.create_unix_connection(
            lambda: protocol, path, **kwds)
        writer = StreamWriter(transport, protocol, reader, loop)
        return reader, writer
    async def start_unix_server(client_connected_cb, path=None, *,
                                loop=None, limit=_DEFAULT_LIMIT, **kwds):
        """Similar to `start_server` but works with UNIX Domain Sockets."""
        if loop is None:
            loop = events.get_event_loop()
        def factory():
            reader = StreamReader(limit=limit, loop=loop)
            protocol = StreamReaderProtocol(reader, client_connected_cb,
                                            loop=loop)
            return protocol
        return await loop.create_unix_server(factory, path, **kwds)
 class FlowControlMixin(protocols.Protocol):
    """Reusable flow control logic for StreamWriter.drain().
    This implements the protocol methods pause_writing(),
    resume_writing() and connection_lost().  If the subclass overrides
    these it must call the super methods.
    StreamWriter.drain() must wait for _drain_helper() coroutine.
    """
    def __init__(self, loop=None):
        if loop is None:
            self._loop = events.get_event_loop()
        else:
            self._loop = loop
        self._paused = False
        self._drain_waiter = None
        self._connection_lost = False
    def pause_writing(self):
        assert not self._paused
        self._paused = True
        if self._loop.get_debug():
            logger.debug("%r pauses writing", self)
    def resume_writing(self):
        assert self._paused
        self._paused = False
        if self._loop.get_debug():
            logger.debug("%r resumes writing", self)
        waiter = self._drain_waiter
        if waiter is not None:
            self._drain_waiter = None
            if not waiter.done():
                waiter.set_result(None)
    def connection_lost(self, exc):
        self._connection_lost = True
        # Wake up the writer if currently paused.
        if not self._paused:
            return
        waiter = self._drain_waiter
        if waiter is None:
            return
        self._drain_waiter = None
        if waiter.done():
            return
        if exc is None:
            waiter.set_result(None)
        else:
            waiter.set_exception(exc)
    async def _drain_helper(self):
        if self._connection_lost:
            raise ConnectionResetError('Connection lost')
        if not self._paused:
            return
        waiter = self._drain_waiter
        assert waiter is None or waiter.cancelled()
        waiter = self._loop.create_future()
        self._drain_waiter = waiter
        await waiter
 class StreamReaderProtocol(FlowControlMixin, protocols.Protocol):
    """Helper class to adapt between Protocol and StreamReader.
    (This is a helper class instead of making StreamReader itself a
    Protocol subclass, because the StreamReader has other potential
    uses, and to prevent the user of the StreamReader to accidentally
    call inappropriate methods of the protocol.)
    """
    def __init__(self, stream_reader, client_connected_cb=None, loop=None):
        super().__init__(loop=loop)
        self._stream_reader = stream_reader
        self._stream_writer = None
        self._client_connected_cb = client_connected_cb
        self._over_ssl = False
        self._closed = self._loop.create_future()
    def connection_made(self, transport):
        self._stream_reader.set_transport(transport)
        self._over_ssl = transport.get_extra_info('sslcontext') is not None
        if self._client_connected_cb is not None:
            self._stream_writer = StreamWriter(transport, self,
                                               self._stream_reader,
                                               self._loop)
            res = self._client_connected_cb(self._stream_reader,
                                            self._stream_writer)
            if coroutines.iscoroutine(res):
                self._loop.create_task(res)
    def connection_lost(self, exc):
        if self._stream_reader is not None:
            if exc is None:
                self._stream_reader.feed_eof()
            else:
                self._stream_reader.set_exception(exc)
        if not self._closed.done():
            if exc is None:
                self._closed.set_result(None)
            else:
                self._closed.set_exception(exc)
        super().connection_lost(exc)
        self._stream_reader = None
        self._stream_writer = None
    def data_received(self, data):
        self._stream_reader.feed_data(data)
    def eof_received(self):
        self._stream_reader.feed_eof()
        if self._over_ssl:
            # Prevent a warning in SSLProtocol.eof_received:
            # "returning true from eof_received()
            # has no effect when using ssl"
            return False
        return True
    def __del__(self):
        # Prevent reports about unhandled exceptions.
        # Better than self._closed._log_traceback = False hack
        closed = self._closed
        if closed.done() and not closed.cancelled():
            closed.exception()
 class StreamWriter:
    """Wraps a Transport.
    This exposes write(), writelines(), [can_]write_eof(),
    get_extra_info() and close().  It adds drain() which returns an
    optional Future on which you can wait for flow control.  It also
    adds a transport property which references the Transport
    directly.
    """
    def __init__(self, transport, protocol, reader, loop):
        self._transport = transport
        self._protocol = protocol
        # drain() expects that the reader has an exception() method
        assert reader is None or isinstance(reader, StreamReader)
        self._reader = reader
        self._loop = loop
    def __repr__(self):
        info = [self.__class__.__name__, f'transport={self._transport!r}']
        if self._reader is not None:
            info.append(f'reader={self._reader!r}')
        return '<{}>'.format(' '.join(info))
    @property
    def transport(self):
        return self._transport
    def write(self, data):
        self._transport.write(data)
    def writelines(self, data):
        self._transport.writelines(data)
    def write_eof(self):
        return self._transport.write_eof()
    def can_write_eof(self):
        return self._transport.can_write_eof()
    def close(self):
        return self._transport.close()
    def is_closing(self):
        return self._transport.is_closing()
    async def wait_closed(self):
        await self._protocol._closed
    def get_extra_info(self, name, default=None):
        return self._transport.get_extra_info(name, default)
    async def drain(self):
        """Flush the write buffer.
        The intended use is to write
          w.write(data)
          await w.drain()
        """
        if self._reader is not None:
            exc = self._reader.exception()
            if exc is not None:
                raise exc
        if self._transport.is_closing():
            # Yield to the event loop so connection_lost() may be
            # called.  Without this, _drain_helper() would return
            # immediately, and code that calls
            #     write(...); await drain()
            # in a loop would never call connection_lost(), so it
            # would not see an error when the socket is closed.
            await sleep(0, loop=self._loop)
        await self._protocol._drain_helper()
 class StreamReader:
    def __init__(self, limit=_DEFAULT_LIMIT, loop=None):
        # The line length limit is  a security feature;
        # it also doubles as half the buffer limit.
        if limit <= 0:
            raise ValueError('Limit cannot be <= 0')
        self._limit = limit
        if loop is None:
            self._loop = events.get_event_loop()
        else:
            self._loop = loop
        self._buffer = bytearray()
        self._eof = False    # Whether we're done.
        self._waiter = None  # A future used by _wait_for_data()
        self._exception = None
        self._transport = None
        self._paused = False
    def __repr__(self):
        info = ['StreamReader']
        if self._buffer:
            info.append(f'{len(self._buffer)} bytes')
        if self._eof:
            info.append('eof')
        if self._limit != _DEFAULT_LIMIT:
            info.append(f'limit={self._limit}')
        if self._waiter:
            info.append(f'waiter={self._waiter!r}')
        if self._exception:
            info.append(f'exception={self._exception!r}')
        if self._transport:
            info.append(f'transport={self._transport!r}')
        if self._paused:
            info.append('paused')
        return '<{}>'.format(' '.join(info))
    def exception(self):
        return self._exception
    def set_exception(self, exc):
        self._exception = exc
        waiter = self._waiter
        if waiter is not None:
            self._waiter = None
            if not waiter.cancelled():
                waiter.set_exception(exc)
    def _wakeup_waiter(self):
        """Wakeup read*() functions waiting for data or EOF."""
        waiter = self._waiter
        if waiter is not None:
            self._waiter = None
            if not waiter.cancelled():
                waiter.set_result(None)
    def set_transport(self, transport):
        assert self._transport is None, 'Transport already set'
        self._transport = transport
    def _maybe_resume_transport(self):
        if self._paused and len(self._buffer) <= self._limit:
            self._paused = False
            self._transport.resume_reading()
    def feed_eof(self):
        self._eof = True
        self._wakeup_waiter()
    def at_eof(self):
        """Return True if the buffer is empty and 'feed_eof' was called."""
        return self._eof and not self._buffer
    def feed_data(self, data):
        assert not self._eof, 'feed_data after feed_eof'
        if not data:
            return
        self._buffer.extend(data)
        self._wakeup_waiter()
        if (self._transport is not None and
                not self._paused and
                len(self._buffer) > 2 * self._limit):
            try:
                self._transport.pause_reading()
            except NotImplementedError:
                # The transport can't be paused.
                # We'll just have to buffer all data.
                # Forget the transport so we don't keep trying.
                self._transport = None
            else:
                self._paused = True
    async def _wait_for_data(self, func_name):
        """Wait until feed_data() or feed_eof() is called.
        If stream was paused, automatically resume it.
        """
        # StreamReader uses a future to link the protocol feed_data() method
        # to a read coroutine. Running two read coroutines at the same time
        # would have an unexpected behaviour. It would not possible to know
        # which coroutine would get the next data.
        if self._waiter is not None:
            raise RuntimeError(
                f'{func_name}() called while another coroutine is '
                f'already waiting for incoming data')
        assert not self._eof, '_wait_for_data after EOF'
        # Waiting for data while paused will make deadlock, so prevent it.
        # This is essential for readexactly(n) for case when n > self._limit.
        if self._paused:
            self._paused = False
            self._transport.resume_reading()
        self._waiter = self._loop.create_future()
        try:
            await self._waiter
        finally:
            self._waiter = None
    async def readline(self):
        """Read chunk of data from the stream until newline (b'\n') is found.
        On success, return chunk that ends with newline. If only partial
        line can be read due to EOF, return incomplete line without
        terminating newline. When EOF was reached while no bytes read, empty
        bytes object is returned.
        If limit is reached, ValueError will be raised. In that case, if
        newline was found, complete line including newline will be removed
        from internal buffer. Else, internal buffer will be cleared. Limit is
        compared against part of the line without newline.
        If stream was paused, this function will automatically resume it if
        needed.
        """
        sep = b'\n'
        seplen = len(sep)
        try:
            line = await self.readuntil(sep)
        except IncompleteReadError as e:
            return e.partial
        except LimitOverrunError as e:
            if self._buffer.startswith(sep, e.consumed):
                del self._buffer[:e.consumed + seplen]
            else:
                self._buffer.clear()
            self._maybe_resume_transport()
            raise ValueError(e.args[0])
        return line
    async def readuntil(self, separator=b'\n'):
        """Read data from the stream until ``separator`` is found.
        On success, the data and separator will be removed from the
        internal buffer (consumed). Returned data will include the
        separator at the end.
        Configured stream limit is used to check result. Limit sets the
        maximal length of data that can be returned, not counting the
        separator.
        If an EOF occurs and the complete separator is still not found,
        an IncompleteReadError exception will be raised, and the internal
        buffer will be reset.  The IncompleteReadError.partial attribute
        may contain the separator partially.
        If the data cannot be read because of over limit, a
        LimitOverrunError exception  will be raised, and the data
        will be left in the internal buffer, so it can be read again.
        """
        seplen = len(separator)
        if seplen == 0:
            raise ValueError('Separator should be at least one-byte string')
        if self._exception is not None:
            raise self._exception
        # Consume whole buffer except last bytes, which length is
        # one less than seplen. Let's check corner cases with
        # separator='SEPARATOR':
        # * we have received almost complete separator (without last
        #   byte). i.e buffer='some textSEPARATO'. In this case we
        #   can safely consume len(separator) - 1 bytes.
        # * last byte of buffer is first byte of separator, i.e.
        #   buffer='abcdefghijklmnopqrS'. We may safely consume
        #   everything except that last byte, but this require to
        #   analyze bytes of buffer that match partial separator.
        #   This is slow and/or require FSM. For this case our
        #   implementation is not optimal, since require rescanning
        #   of data that is known to not belong to separator. In
        #   real world, separator will not be so long to notice
        #   performance problems. Even when reading MIME-encoded
        #   messages :)
        # `offset` is the number of bytes from the beginning of the buffer
        # where there is no occurrence of `separator`.
        offset = 0
        # Loop until we find `separator` in the buffer, exceed the buffer size,
        # or an EOF has happened.
        while True:
            buflen = len(self._buffer)
            # Check if we now have enough data in the buffer for `separator` to
            # fit.
            if buflen - offset >= seplen:
                isep = self._buffer.find(separator, offset)
                if isep != -1:
                    # `separator` is in the buffer. `isep` will be used later
                    # to retrieve the data.
                    break
                # see upper comment for explanation.
                offset = buflen + 1 - seplen
                if offset > self._limit:
                    raise LimitOverrunError(
                        'Separator is not found, and chunk exceed the limit',
                        offset)
            # Complete message (with full separator) may be present in buffer
            # even when EOF flag is set. This may happen when the last chunk
            # adds data which makes separator be found. That's why we check for
            # EOF *ater* inspecting the buffer.
            if self._eof:
                chunk = bytes(self._buffer)
                self._buffer.clear()
                raise IncompleteReadError(chunk, None)
            # _wait_for_data() will resume reading if stream was paused.
            await self._wait_for_data('readuntil')
        if isep > self._limit:
            raise LimitOverrunError(
                'Separator is found, but chunk is longer than limit', isep)
        chunk = self._buffer[:isep + seplen]
        del self._buffer[:isep + seplen]
        self._maybe_resume_transport()
        return bytes(chunk)
    async def read(self, n=-1):
        """Read up to `n` bytes from the stream.
        If n is not provided, or set to -1, read until EOF and return all read
        bytes. If the EOF was received and the internal buffer is empty, return
        an empty bytes object.
        If n is zero, return empty bytes object immediately.
        If n is positive, this function try to read `n` bytes, and may return
        less or equal bytes than requested, but at least one byte. If EOF was
        received before any byte is read, this function returns empty byte
        object.
        Returned value is not limited with limit, configured at stream
        creation.
        If stream was paused, this function will automatically resume it if
        needed.
        """
        if self._exception is not None:
            raise self._exception
        if n == 0:
            return b''
        if n < 0:
            # This used to just loop creating a new waiter hoping to
            # collect everything in self._buffer, but that would
            # deadlock if the subprocess sends more than self.limit
            # bytes.  So just call self.read(self._limit) until EOF.
            blocks = []
            while True:
                block = await self.read(self._limit)
                if not block:
                    break
                blocks.append(block)
            return b''.join(blocks)
        if not self._buffer and not self._eof:
            await self._wait_for_data('read')
        # This will work right even if buffer is less than n bytes
        data = bytes(self._buffer[:n])
        del self._buffer[:n]
        self._maybe_resume_transport()
        return data
    async def readexactly(self, n):
        """Read exactly `n` bytes.
        Raise an IncompleteReadError if EOF is reached before `n` bytes can be
        read. The IncompleteReadError.partial attribute of the exception will
        contain the partial read bytes.
        if n is zero, return empty bytes object.
        Returned value is not limited with limit, configured at stream
        creation.
        If stream was paused, this function will automatically resume it if
        needed.
        """
        if n < 0:
            raise ValueError('readexactly size can not be less than zero')
        if self._exception is not None:
            raise self._exception
        if n == 0:
            return b''
        while len(self._buffer) < n:
            if self._eof:
                incomplete = bytes(self._buffer)
                self._buffer.clear()
                raise IncompleteReadError(incomplete, n)
            await self._wait_for_data('readexactly')
        if len(self._buffer) == n:
            data = bytes(self._buffer)
            self._buffer.clear()
        else:
            data = bytes(self._buffer[:n])
            del self._buffer[:n]
        self._maybe_resume_transport()
        return data
    def __aiter__(self):
        return self
    async def __anext__(self):
        val = await self.readline()
        if val == b'':
            raise StopAsyncIteration
        return val
--- a/Lib/asyncio/subprocess.py
+++ b/Lib/asyncio/subprocess.py
@ -0,0 +1,218 @@
 __all__ = 'create_subprocess_exec', 'create_subprocess_shell'
 import subprocess
 from . import events
 from . import protocols
 from . import streams
 from . import tasks
 from .log import logger
 PIPE = subprocess.PIPE
 STDOUT = subprocess.STDOUT
 DEVNULL = subprocess.DEVNULL
 class SubprocessStreamProtocol(streams.FlowControlMixin,
                               protocols.SubprocessProtocol):
    """Like StreamReaderProtocol, but for a subprocess."""
    def __init__(self, limit, loop):
        super().__init__(loop=loop)
        self._limit = limit
        self.stdin = self.stdout = self.stderr = None
        self._transport = None
        self._process_exited = False
        self._pipe_fds = []
    def __repr__(self):
        info = [self.__class__.__name__]
        if self.stdin is not None:
            info.append(f'stdin={self.stdin!r}')
        if self.stdout is not None:
            info.append(f'stdout={self.stdout!r}')
        if self.stderr is not None:
            info.append(f'stderr={self.stderr!r}')
        return '<{}>'.format(' '.join(info))
    def connection_made(self, transport):
        self._transport = transport
        stdout_transport = transport.get_pipe_transport(1)
        if stdout_transport is not None:
            self.stdout = streams.StreamReader(limit=self._limit,
                                               loop=self._loop)
            self.stdout.set_transport(stdout_transport)
            self._pipe_fds.append(1)
        stderr_transport = transport.get_pipe_transport(2)
        if stderr_transport is not None:
            self.stderr = streams.StreamReader(limit=self._limit,
                                               loop=self._loop)
            self.stderr.set_transport(stderr_transport)
            self._pipe_fds.append(2)
        stdin_transport = transport.get_pipe_transport(0)
        if stdin_transport is not None:
            self.stdin = streams.StreamWriter(stdin_transport,
                                              protocol=self,
                                              reader=None,
                                              loop=self._loop)
    def pipe_data_received(self, fd, data):
        if fd == 1:
            reader = self.stdout
        elif fd == 2:
            reader = self.stderr
        else:
            reader = None
        if reader is not None:
            reader.feed_data(data)
    def pipe_connection_lost(self, fd, exc):
        if fd == 0:
            pipe = self.stdin
            if pipe is not None:
                pipe.close()
            self.connection_lost(exc)
            return
        if fd == 1:
            reader = self.stdout
        elif fd == 2:
            reader = self.stderr
        else:
            reader = None
        if reader is not None:
            if exc is None:
                reader.feed_eof()
            else:
                reader.set_exception(exc)
        if fd in self._pipe_fds:
            self._pipe_fds.remove(fd)
        self._maybe_close_transport()
    def process_exited(self):
        self._process_exited = True
        self._maybe_close_transport()
    def _maybe_close_transport(self):
        if len(self._pipe_fds) == 0 and self._process_exited:
            self._transport.close()
            self._transport = None
 class Process:
    def __init__(self, transport, protocol, loop):
        self._transport = transport
        self._protocol = protocol
        self._loop = loop
        self.stdin = protocol.stdin
        self.stdout = protocol.stdout
        self.stderr = protocol.stderr
        self.pid = transport.get_pid()
    def __repr__(self):
        return f'<{self.__class__.__name__} {self.pid}>'
    @property
    def returncode(self):
        return self._transport.get_returncode()
    async def wait(self):
        """Wait until the process exit and return the process return code."""
        return await self._transport._wait()
    def send_signal(self, signal):
        self._transport.send_signal(signal)
    def terminate(self):
        self._transport.terminate()
    def kill(self):
        self._transport.kill()
    async def _feed_stdin(self, input):
        debug = self._loop.get_debug()
        self.stdin.write(input)
        if debug:
            logger.debug(
                '%r communicate: feed stdin (%s bytes)', self, len(input))
        try:
            await self.stdin.drain()
        except (BrokenPipeError, ConnectionResetError) as exc:
            # communicate() ignores BrokenPipeError and ConnectionResetError
            if debug:
                logger.debug('%r communicate: stdin got %r', self, exc)
        if debug:
            logger.debug('%r communicate: close stdin', self)
        self.stdin.close()
    async def _noop(self):
        return None
    async def _read_stream(self, fd):
        transport = self._transport.get_pipe_transport(fd)
        if fd == 2:
            stream = self.stderr
        else:
            assert fd == 1
            stream = self.stdout
        if self._loop.get_debug():
            name = 'stdout' if fd == 1 else 'stderr'
            logger.debug('%r communicate: read %s', self, name)
        output = await stream.read()
        if self._loop.get_debug():
            name = 'stdout' if fd == 1 else 'stderr'
            logger.debug('%r communicate: close %s', self, name)
        transport.close()
        return output
    async def communicate(self, input=None):
        if input is not None:
            stdin = self._feed_stdin(input)
        else:
            stdin = self._noop()
        if self.stdout is not None:
            stdout = self._read_stream(1)
        else:
            stdout = self._noop()
        if self.stderr is not None:
            stderr = self._read_stream(2)
        else:
            stderr = self._noop()
        stdin, stdout, stderr = await tasks.gather(stdin, stdout, stderr,
                                                   loop=self._loop)
        await self.wait()
        return (stdout, stderr)
 async def create_subprocess_shell(cmd, stdin=None, stdout=None, stderr=None,
                                  loop=None, limit=streams._DEFAULT_LIMIT,
                                  **kwds):
    if loop is None:
        loop = events.get_event_loop()
    protocol_factory = lambda: SubprocessStreamProtocol(limit=limit,
                                                        loop=loop)
    transport, protocol = await loop.subprocess_shell(
        protocol_factory,
        cmd, stdin=stdin, stdout=stdout,
        stderr=stderr, **kwds)
    return Process(transport, protocol, loop)
 async def create_subprocess_exec(program, *args, stdin=None, stdout=None,
                                 stderr=None, loop=None,
                                 limit=streams._DEFAULT_LIMIT, **kwds):
    if loop is None:
        loop = events.get_event_loop()
    protocol_factory = lambda: SubprocessStreamProtocol(limit=limit,
                                                        loop=loop)
    transport, protocol = await loop.subprocess_exec(
        protocol_factory,
        program, *args,
        stdin=stdin, stdout=stdout,
        stderr=stderr, **kwds)
    return Process(transport, protocol, loop)
--- a/Lib/asyncio/tasks.py
+++ b/Lib/asyncio/tasks.py
@ -0,0 +1,867 @@
 """Support for tasks, coroutines and the scheduler."""
 __all__ = (
    'Task', 'create_task',
    'FIRST_COMPLETED', 'FIRST_EXCEPTION', 'ALL_COMPLETED',
    'wait', 'wait_for', 'as_completed', 'sleep',
    'gather', 'shield', 'ensure_future', 'run_coroutine_threadsafe',
    'current_task', 'all_tasks',
    '_register_task', '_unregister_task', '_enter_task', '_leave_task',
 )
 import concurrent.futures
 import contextvars
 import functools
 import inspect
 import types
 import warnings
 import weakref
 from . import base_tasks
 from . import coroutines
 from . import events
 from . import futures
 from .coroutines import coroutine
 def current_task(loop=None):
    """Return a currently executed task."""
    if loop is None:
        loop = events.get_running_loop()
    return _current_tasks.get(loop)
 def all_tasks(loop=None):
    """Return a set of all tasks for the loop."""
    if loop is None:
        loop = events.get_running_loop()
    # NB: set(_all_tasks) is required to protect
    # from https://bugs.python.org/issue34970 bug
    return {t for t in list(_all_tasks)
            if futures._get_loop(t) is loop and not t.done()}
 def _all_tasks_compat(loop=None):
    # Different from "all_task()" by returning *all* Tasks, including
    # the completed ones.  Used to implement deprecated "Tasks.all_task()"
    # method.
    if loop is None:
        loop = events.get_event_loop()
    # NB: set(_all_tasks) is required to protect
    # from https://bugs.python.org/issue34970 bug
    return {t for t in list(_all_tasks) if futures._get_loop(t) is loop}
 class Task(futures._PyFuture):  # Inherit Python Task implementation
                                # from a Python Future implementation.
    """A coroutine wrapped in a Future."""
    # An important invariant maintained while a Task not done:
    #
    # - Either _fut_waiter is None, and _step() is scheduled;
    # - or _fut_waiter is some Future, and _step() is *not* scheduled.
    #
    # The only transition from the latter to the former is through
    # _wakeup().  When _fut_waiter is not None, one of its callbacks
    # must be _wakeup().
    # If False, don't log a message if the task is destroyed whereas its
    # status is still pending
    _log_destroy_pending = True
    @classmethod
    def current_task(cls, loop=None):
        """Return the currently running task in an event loop or None.
        By default the current task for the current event loop is returned.
        None is returned when called not in the context of a Task.
        """
        warnings.warn("Task.current_task() is deprecated, "
                      "use asyncio.current_task() instead",
                      PendingDeprecationWarning,
                      stacklevel=2)
        if loop is None:
            loop = events.get_event_loop()
        return current_task(loop)
    @classmethod
    def all_tasks(cls, loop=None):
        """Return a set of all tasks for an event loop.
        By default all tasks for the current event loop are returned.
        """
        warnings.warn("Task.all_tasks() is deprecated, "
                      "use asyncio.all_tasks() instead",
                      PendingDeprecationWarning,
                      stacklevel=2)
        return _all_tasks_compat(loop)
    def __init__(self, coro, *, loop=None):
        super().__init__(loop=loop)
        if self._source_traceback:
            del self._source_traceback[-1]
        if not coroutines.iscoroutine(coro):
            # raise after Future.__init__(), attrs are required for __del__
            # prevent logging for pending task in __del__
            self._log_destroy_pending = False
            raise TypeError(f"a coroutine was expected, got {coro!r}")
        self._must_cancel = False
        self._fut_waiter = None
        self._coro = coro
        self._context = contextvars.copy_context()
        self._loop.call_soon(self.__step, context=self._context)
        _register_task(self)
    def __del__(self):
        if self._state == futures._PENDING and self._log_destroy_pending:
            context = {
                'task': self,
                'message': 'Task was destroyed but it is pending!',
            }
            if self._source_traceback:
                context['source_traceback'] = self._source_traceback
            self._loop.call_exception_handler(context)
        super().__del__()
    def _repr_info(self):
        return base_tasks._task_repr_info(self)
    def set_result(self, result):
        raise RuntimeError('Task does not support set_result operation')
    def set_exception(self, exception):
        raise RuntimeError('Task does not support set_exception operation')
    def get_stack(self, *, limit=None):
        """Return the list of stack frames for this task's coroutine.
        If the coroutine is not done, this returns the stack where it is
        suspended.  If the coroutine has completed successfully or was
        cancelled, this returns an empty list.  If the coroutine was
        terminated by an exception, this returns the list of traceback
        frames.
        The frames are always ordered from oldest to newest.
        The optional limit gives the maximum number of frames to
        return; by default all available frames are returned.  Its
        meaning differs depending on whether a stack or a traceback is
        returned: the newest frames of a stack are returned, but the
        oldest frames of a traceback are returned.  (This matches the
        behavior of the traceback module.)
        For reasons beyond our control, only one stack frame is
        returned for a suspended coroutine.
        """
        return base_tasks._task_get_stack(self, limit)
    def print_stack(self, *, limit=None, file=None):
        """Print the stack or traceback for this task's coroutine.
        This produces output similar to that of the traceback module,
        for the frames retrieved by get_stack().  The limit argument
        is passed to get_stack().  The file argument is an I/O stream
        to which the output is written; by default output is written
        to sys.stderr.
        """
        return base_tasks._task_print_stack(self, limit, file)
    def cancel(self):
        """Request that this task cancel itself.
        This arranges for a CancelledError to be thrown into the
        wrapped coroutine on the next cycle through the event loop.
        The coroutine then has a chance to clean up or even deny
        the request using try/except/finally.
        Unlike Future.cancel, this does not guarantee that the
        task will be cancelled: the exception might be caught and
        acted upon, delaying cancellation of the task or preventing
        cancellation completely.  The task may also return a value or
        raise a different exception.
        Immediately after this method is called, Task.cancelled() will
        not return True (unless the task was already cancelled).  A
        task will be marked as cancelled when the wrapped coroutine
        terminates with a CancelledError exception (even if cancel()
        was not called).
        """
        self._log_traceback = False
        if self.done():
            return False
        if self._fut_waiter is not None:
            if self._fut_waiter.cancel():
                # Leave self._fut_waiter; it may be a Task that
                # catches and ignores the cancellation so we may have
                # to cancel it again later.
                return True
        # It must be the case that self.__step is already scheduled.
        self._must_cancel = True
        return True
    def __step(self, exc=None):
        if self.done():
            raise futures.InvalidStateError(
                f'_step(): already done: {self!r}, {exc!r}')
        if self._must_cancel:
            if not isinstance(exc, futures.CancelledError):
                exc = futures.CancelledError()
            self._must_cancel = False
        coro = self._coro
        self._fut_waiter = None
        _enter_task(self._loop, self)
        # Call either coro.throw(exc) or coro.send(None).
        try:
            if exc is None:
                # We use the `send` method directly, because coroutines
                # don't have `__iter__` and `__next__` methods.
                result = coro.send(None)
            else:
                result = coro.throw(exc)
        except StopIteration as exc:
            if self._must_cancel:
                # Task is cancelled right before coro stops.
                self._must_cancel = False
                super().set_exception(futures.CancelledError())
            else:
                super().set_result(exc.value)
        except futures.CancelledError:
            super().cancel()  # I.e., Future.cancel(self).
        except Exception as exc:
            super().set_exception(exc)
        except BaseException as exc:
            super().set_exception(exc)
            raise
        else:
            blocking = getattr(result, '_asyncio_future_blocking', None)
            if blocking is not None:
                # Yielded Future must come from Future.__iter__().
                if futures._get_loop(result) is not self._loop:
                    new_exc = RuntimeError(
                        f'Task {self!r} got Future '
                        f'{result!r} attached to a different loop')
                    self._loop.call_soon(
                        self.__step, new_exc, context=self._context)
                elif blocking:
                    if result is self:
                        new_exc = RuntimeError(
                            f'Task cannot await on itself: {self!r}')
                        self._loop.call_soon(
                            self.__step, new_exc, context=self._context)
                    else:
                        result._asyncio_future_blocking = False
                        result.add_done_callback(
                            self.__wakeup, context=self._context)
                        self._fut_waiter = result
                        if self._must_cancel:
                            if self._fut_waiter.cancel():
                                self._must_cancel = False
                else:
                    new_exc = RuntimeError(
                        f'yield was used instead of yield from '
                        f'in task {self!r} with {result!r}')
                    self._loop.call_soon(
                        self.__step, new_exc, context=self._context)
            elif result is None:
                # Bare yield relinquishes control for one event loop iteration.
                self._loop.call_soon(self.__step, context=self._context)
            elif inspect.isgenerator(result):
                # Yielding a generator is just wrong.
                new_exc = RuntimeError(
                    f'yield was used instead of yield from for '
                    f'generator in task {self!r} with {result!r}')
                self._loop.call_soon(
                    self.__step, new_exc, context=self._context)
            else:
                # Yielding something else is an error.
                new_exc = RuntimeError(f'Task got bad yield: {result!r}')
                self._loop.call_soon(
                    self.__step, new_exc, context=self._context)
        finally:
            _leave_task(self._loop, self)
            self = None  # Needed to break cycles when an exception occurs.
    def __wakeup(self, future):
        try:
            future.result()
        except Exception as exc:
            # This may also be a cancellation.
            self.__step(exc)
        else:
            # Don't pass the value of `future.result()` explicitly,
            # as `Future.__iter__` and `Future.__await__` don't need it.
            # If we call `_step(value, None)` instead of `_step()`,
            # Python eval loop would use `.send(value)` method call,
            # instead of `__next__()`, which is slower for futures
            # that return non-generator iterators from their `__iter__`.
            self.__step()
        self = None  # Needed to break cycles when an exception occurs.
 _PyTask = Task
 try:
    import _asyncio
 except ImportError:
    pass
 else:
    # _CTask is needed for tests.
    Task = _CTask = _asyncio.Task
 def create_task(coro):
    """Schedule the execution of a coroutine object in a spawn task.
    Return a Task object.
    """
    loop = events.get_running_loop()
    return loop.create_task(coro)
 # wait() and as_completed() similar to those in PEP 3148.
 FIRST_COMPLETED = concurrent.futures.FIRST_COMPLETED
 FIRST_EXCEPTION = concurrent.futures.FIRST_EXCEPTION
 ALL_COMPLETED = concurrent.futures.ALL_COMPLETED
 async def wait(fs, *, loop=None, timeout=None, return_when=ALL_COMPLETED):
    """Wait for the Futures and coroutines given by fs to complete.
    The sequence futures must not be empty.
    Coroutines will be wrapped in Tasks.
    Returns two sets of Future: (done, pending).
    Usage:
        done, pending = await asyncio.wait(fs)
    Note: This does not raise TimeoutError! Futures that aren't done
    when the timeout occurs are returned in the second set.
    """
    if futures.isfuture(fs) or coroutines.iscoroutine(fs):
        raise TypeError(f"expect a list of futures, not {type(fs).__name__}")
    if not fs:
        raise ValueError('Set of coroutines/Futures is empty.')
    if return_when not in (FIRST_COMPLETED, FIRST_EXCEPTION, ALL_COMPLETED):
        raise ValueError(f'Invalid return_when value: {return_when}')
    if loop is None:
        loop = events.get_event_loop()
    fs = {ensure_future(f, loop=loop) for f in set(fs)}
    return await _wait(fs, timeout, return_when, loop)
 def _release_waiter(waiter, *args):
    if not waiter.done():
        waiter.set_result(None)
 async def wait_for(fut, timeout, *, loop=None):
    """Wait for the single Future or coroutine to complete, with timeout.
    Coroutine will be wrapped in Task.
    Returns result of the Future or coroutine.  When a timeout occurs,
    it cancels the task and raises TimeoutError.  To avoid the task
    cancellation, wrap it in shield().
    If the wait is cancelled, the task is also cancelled.
    This function is a coroutine.
    """
    if loop is None:
        loop = events.get_event_loop()
    if timeout is None:
        return await fut
    if timeout <= 0:
        fut = ensure_future(fut, loop=loop)
        if fut.done():
            return fut.result()
        fut.cancel()
        raise futures.TimeoutError()
    waiter = loop.create_future()
    timeout_handle = loop.call_later(timeout, _release_waiter, waiter)
    cb = functools.partial(_release_waiter, waiter)
    fut = ensure_future(fut, loop=loop)
    fut.add_done_callback(cb)
    try:
        # wait until the future completes or the timeout
        try:
            await waiter
        except futures.CancelledError:
            fut.remove_done_callback(cb)
            fut.cancel()
            raise
        if fut.done():
            return fut.result()
        else:
            fut.remove_done_callback(cb)
            # We must ensure that the task is not running
            # after wait_for() returns.
            # See https://bugs.python.org/issue32751
            await _cancel_and_wait(fut, loop=loop)
            raise futures.TimeoutError()
    finally:
        timeout_handle.cancel()
 async def _wait(fs, timeout, return_when, loop):
    """Internal helper for wait().
    The fs argument must be a collection of Futures.
    """
    assert fs, 'Set of Futures is empty.'
    waiter = loop.create_future()
    timeout_handle = None
    if timeout is not None:
        timeout_handle = loop.call_later(timeout, _release_waiter, waiter)
    counter = len(fs)
    def _on_completion(f):
        nonlocal counter
        counter -= 1
        if (counter <= 0 or
            return_when == FIRST_COMPLETED or
            return_when == FIRST_EXCEPTION and (not f.cancelled() and
                                                f.exception() is not None)):
            if timeout_handle is not None:
                timeout_handle.cancel()
            if not waiter.done():
                waiter.set_result(None)
    for f in fs:
        f.add_done_callback(_on_completion)
    try:
        await waiter
    finally:
        if timeout_handle is not None:
            timeout_handle.cancel()
    done, pending = set(), set()
    for f in fs:
        f.remove_done_callback(_on_completion)
        if f.done():
            done.add(f)
        else:
            pending.add(f)
    return done, pending
 async def _cancel_and_wait(fut, loop):
    """Cancel the *fut* future or task and wait until it completes."""
    waiter = loop.create_future()
    cb = functools.partial(_release_waiter, waiter)
    fut.add_done_callback(cb)
    try:
        fut.cancel()
        # We cannot wait on *fut* directly to make
        # sure _cancel_and_wait itself is reliably cancellable.
        await waiter
    finally:
        fut.remove_done_callback(cb)
 # This is *not* a @coroutine!  It is just an iterator (yielding Futures).
 def as_completed(fs, *, loop=None, timeout=None):
    """Return an iterator whose values are coroutines.
    When waiting for the yielded coroutines you'll get the results (or
    exceptions!) of the original Futures (or coroutines), in the order
    in which and as soon as they complete.
    This differs from PEP 3148; the proper way to use this is:
        for f in as_completed(fs):
            result = await f  # The 'await' may raise.
            # Use result.
    If a timeout is specified, the 'await' will raise
    TimeoutError when the timeout occurs before all Futures are done.
    Note: The futures 'f' are not necessarily members of fs.
    """
    if futures.isfuture(fs) or coroutines.iscoroutine(fs):
        raise TypeError(f"expect a list of futures, not {type(fs).__name__}")
    loop = loop if loop is not None else events.get_event_loop()
    todo = {ensure_future(f, loop=loop) for f in set(fs)}
    from .queues import Queue  # Import here to avoid circular import problem.
    done = Queue(loop=loop)
    timeout_handle = None
    def _on_timeout():
        for f in todo:
            f.remove_done_callback(_on_completion)
            done.put_nowait(None)  # Queue a dummy value for _wait_for_one().
        todo.clear()  # Can't do todo.remove(f) in the loop.
    def _on_completion(f):
        if not todo:
            return  # _on_timeout() was here first.
        todo.remove(f)
        done.put_nowait(f)
        if not todo and timeout_handle is not None:
            timeout_handle.cancel()
    async def _wait_for_one():
        f = await done.get()
        if f is None:
            # Dummy value from _on_timeout().
            raise futures.TimeoutError
        return f.result()  # May raise f.exception().
    for f in todo:
        f.add_done_callback(_on_completion)
    if todo and timeout is not None:
        timeout_handle = loop.call_later(timeout, _on_timeout)
    for _ in range(len(todo)):
        yield _wait_for_one()
@types.coroutine
 def __sleep0():
    """Skip one event loop run cycle.
    This is a private helper for 'asyncio.sleep()', used
    when the 'delay' is set to 0.  It uses a bare 'yield'
    expression (which Task.__step knows how to handle)
    instead of creating a Future object.
    """
    yield
 async def sleep(delay, result=None, *, loop=None):
    """Coroutine that completes after a given time (in seconds)."""
    if delay <= 0:
        await __sleep0()
        return result
    if loop is None:
        loop = events.get_event_loop()
    future = loop.create_future()
    h = loop.call_later(delay,
                        futures._set_result_unless_cancelled,
                        future, result)
    try:
        return await future
    finally:
        h.cancel()
 def ensure_future(coro_or_future, *, loop=None):
    """Wrap a coroutine or an awaitable in a future.
    If the argument is a Future, it is returned directly.
    """
    if coroutines.iscoroutine(coro_or_future):
        if loop is None:
            loop = events.get_event_loop()
        task = loop.create_task(coro_or_future)
        if task._source_traceback:
            del task._source_traceback[-1]
        return task
    elif futures.isfuture(coro_or_future):
        if loop is not None and loop is not futures._get_loop(coro_or_future):
            raise ValueError('loop argument must agree with Future')
        return coro_or_future
    elif inspect.isawaitable(coro_or_future):
        return ensure_future(_wrap_awaitable(coro_or_future), loop=loop)
    else:
        raise TypeError('An asyncio.Future, a coroutine or an awaitable is '
                        'required')
@coroutine
 def _wrap_awaitable(awaitable):
    """Helper for asyncio.ensure_future().
    Wraps awaitable (an object with __await__) into a coroutine
    that will later be wrapped in a Task by ensure_future().
    """
    return (yield from awaitable.__await__())
 class _GatheringFuture(futures.Future):
    """Helper for gather().
    This overrides cancel() to cancel all the children and act more
    like Task.cancel(), which doesn't immediately mark itself as
    cancelled.
    """
    def __init__(self, children, *, loop=None):
        super().__init__(loop=loop)
        self._children = children
        self._cancel_requested = False
    def cancel(self):
        if self.done():
            return False
        ret = False
        for child in self._children:
            if child.cancel():
                ret = True
        if ret:
            # If any child tasks were actually cancelled, we should
            # propagate the cancellation request regardless of
            # *return_exceptions* argument.  See issue 32684.
            self._cancel_requested = True
        return ret
 def gather(*coros_or_futures, loop=None, return_exceptions=False):
    """Return a future aggregating results from the given coroutines/futures.
    Coroutines will be wrapped in a future and scheduled in the event
    loop. They will not necessarily be scheduled in the same order as
    passed in.
    All futures must share the same event loop.  If all the tasks are
    done successfully, the returned future's result is the list of
    results (in the order of the original sequence, not necessarily
    the order of results arrival).  If *return_exceptions* is True,
    exceptions in the tasks are treated the same as successful
    results, and gathered in the result list; otherwise, the first
    raised exception will be immediately propagated to the returned
    future.
    Cancellation: if the outer Future is cancelled, all children (that
    have not completed yet) are also cancelled.  If any child is
    cancelled, this is treated as if it raised CancelledError --
    the outer Future is *not* cancelled in this case.  (This is to
    prevent the cancellation of one child to cause other children to
    be cancelled.)
    """
    if not coros_or_futures:
        if loop is None:
            loop = events.get_event_loop()
        outer = loop.create_future()
        outer.set_result([])
        return outer
    def _done_callback(fut):
        nonlocal nfinished
        nfinished += 1
        if outer.done():
            if not fut.cancelled():
                # Mark exception retrieved.
                fut.exception()
            return
        if not return_exceptions:
            if fut.cancelled():
                # Check if 'fut' is cancelled first, as
                # 'fut.exception()' will *raise* a CancelledError
                # instead of returning it.
                exc = futures.CancelledError()
                outer.set_exception(exc)
                return
            else:
                exc = fut.exception()
                if exc is not None:
                    outer.set_exception(exc)
                    return
        if nfinished == nfuts:
            # All futures are done; create a list of results
            # and set it to the 'outer' future.
            results = []
            for fut in children:
                if fut.cancelled():
                    # Check if 'fut' is cancelled first, as
                    # 'fut.exception()' will *raise* a CancelledError
                    # instead of returning it.
                    res = futures.CancelledError()
                else:
                    res = fut.exception()
                    if res is None:
                        res = fut.result()
                results.append(res)
            if outer._cancel_requested:
                # If gather is being cancelled we must propagate the
                # cancellation regardless of *return_exceptions* argument.
                # See issue 32684.
                outer.set_exception(futures.CancelledError())
            else:
                outer.set_result(results)
    arg_to_fut = {}
    children = []
    nfuts = 0
    nfinished = 0
    for arg in coros_or_futures:
        if arg not in arg_to_fut:
            fut = ensure_future(arg, loop=loop)
            if loop is None:
                loop = futures._get_loop(fut)
            if fut is not arg:
                # 'arg' was not a Future, therefore, 'fut' is a new
                # Future created specifically for 'arg'.  Since the caller
                # can't control it, disable the "destroy pending task"
                # warning.
                fut._log_destroy_pending = False
            nfuts += 1
            arg_to_fut[arg] = fut
            fut.add_done_callback(_done_callback)
        else:
            # There's a duplicate Future object in coros_or_futures.
            fut = arg_to_fut[arg]
        children.append(fut)
    outer = _GatheringFuture(children, loop=loop)
    return outer
 def shield(arg, *, loop=None):
    """Wait for a future, shielding it from cancellation.
    The statement
        res = await shield(something())
    is exactly equivalent to the statement
        res = await something()
    *except* that if the coroutine containing it is cancelled, the
    task running in something() is not cancelled.  From the POV of
    something(), the cancellation did not happen.  But its caller is
    still cancelled, so the yield-from expression still raises
    CancelledError.  Note: If something() is cancelled by other means
    this will still cancel shield().
    If you want to completely ignore cancellation (not recommended)
    you can combine shield() with a try/except clause, as follows:
        try:
            res = await shield(something())
        except CancelledError:
            res = None
    """
    inner = ensure_future(arg, loop=loop)
    if inner.done():
        # Shortcut.
        return inner
    loop = futures._get_loop(inner)
    outer = loop.create_future()
    def _done_callback(inner):
        if outer.cancelled():
            if not inner.cancelled():
                # Mark inner's result as retrieved.
                inner.exception()
            return
        if inner.cancelled():
            outer.cancel()
        else:
            exc = inner.exception()
            if exc is not None:
                outer.set_exception(exc)
            else:
                outer.set_result(inner.result())
    inner.add_done_callback(_done_callback)
    return outer
 def run_coroutine_threadsafe(coro, loop):
    """Submit a coroutine object to a given event loop.
    Return a concurrent.futures.Future to access the result.
    """
    if not coroutines.iscoroutine(coro):
        raise TypeError('A coroutine object is required')
    future = concurrent.futures.Future()
    def callback():
        try:
            futures._chain_future(ensure_future(coro, loop=loop), future)
        except Exception as exc:
            if future.set_running_or_notify_cancel():
                future.set_exception(exc)
            raise
    loop.call_soon_threadsafe(callback)
    return future
 # WeakSet containing all alive tasks.
 _all_tasks = weakref.WeakSet()
 # Dictionary containing tasks that are currently active in
 # all running event loops.  {EventLoop: Task}
 _current_tasks = {}
 def _register_task(task):
    """Register a new task in asyncio as executed by loop."""
    _all_tasks.add(task)
 def _enter_task(loop, task):
    current_task = _current_tasks.get(loop)
    if current_task is not None:
        raise RuntimeError(f"Cannot enter into task {task!r} while another "
                           f"task {current_task!r} is being executed.")
    _current_tasks[loop] = task
 def _leave_task(loop, task):
    current_task = _current_tasks.get(loop)
    if current_task is not task:
        raise RuntimeError(f"Leaving task {task!r} does not match "
                           f"the current task {current_task!r}.")
    del _current_tasks[loop]
 def _unregister_task(task):
    """Unregister a task."""
    _all_tasks.discard(task)
 _py_register_task = _register_task
 _py_unregister_task = _unregister_task
 _py_enter_task = _enter_task
 _py_leave_task = _leave_task
 try:
    from _asyncio import (_register_task, _unregister_task,
                          _enter_task, _leave_task,
                          _all_tasks, _current_tasks)
 except ImportError:
    pass
 else:
    _c_register_task = _register_task
    _c_unregister_task = _unregister_task
    _c_enter_task = _enter_task
    _c_leave_task = _leave_task
--- a/Lib/asyncio/transports.py
+++ b/Lib/asyncio/transports.py
@ -0,0 +1,311 @@
 """Abstract Transport class."""
 __all__ = (
    'BaseTransport', 'ReadTransport', 'WriteTransport',
    'Transport', 'DatagramTransport', 'SubprocessTransport',
 )
 class BaseTransport:
    """Base class for transports."""
    def __init__(self, extra=None):
        if extra is None:
            extra = {}
        self._extra = extra
    def get_extra_info(self, name, default=None):
        """Get optional transport information."""
        return self._extra.get(name, default)
    def is_closing(self):
        """Return True if the transport is closing or closed."""
        raise NotImplementedError
    def close(self):
        """Close the transport.
        Buffered data will be flushed asynchronously.  No more data
        will be received.  After all buffered data is flushed, the
        protocol's connection_lost() method will (eventually) called
        with None as its argument.
        """
        raise NotImplementedError
    def set_protocol(self, protocol):
        """Set a new protocol."""
        raise NotImplementedError
    def get_protocol(self):
        """Return the current protocol."""
        raise NotImplementedError
 class ReadTransport(BaseTransport):
    """Interface for read-only transports."""
    def is_reading(self):
        """Return True if the transport is receiving."""
        raise NotImplementedError
    def pause_reading(self):
        """Pause the receiving end.
        No data will be passed to the protocol's data_received()
        method until resume_reading() is called.
        """
        raise NotImplementedError
    def resume_reading(self):
        """Resume the receiving end.
        Data received will once again be passed to the protocol's
        data_received() method.
        """
        raise NotImplementedError
 class WriteTransport(BaseTransport):
    """Interface for write-only transports."""
    def set_write_buffer_limits(self, high=None, low=None):
        """Set the high- and low-water limits for write flow control.
        These two values control when to call the protocol's
        pause_writing() and resume_writing() methods.  If specified,
        the low-water limit must be less than or equal to the
        high-water limit.  Neither value can be negative.
        The defaults are implementation-specific.  If only the
        high-water limit is given, the low-water limit defaults to an
        implementation-specific value less than or equal to the
        high-water limit.  Setting high to zero forces low to zero as
        well, and causes pause_writing() to be called whenever the
        buffer becomes non-empty.  Setting low to zero causes
        resume_writing() to be called only once the buffer is empty.
        Use of zero for either limit is generally sub-optimal as it
        reduces opportunities for doing I/O and computation
        concurrently.
        """
        raise NotImplementedError
    def get_write_buffer_size(self):
        """Return the current size of the write buffer."""
        raise NotImplementedError
    def write(self, data):
        """Write some data bytes to the transport.
        This does not block; it buffers the data and arranges for it
        to be sent out asynchronously.
        """
        raise NotImplementedError
    def writelines(self, list_of_data):
        """Write a list (or any iterable) of data bytes to the transport.
        The default implementation concatenates the arguments and
        calls write() on the result.
        """
        data = b''.join(list_of_data)
        self.write(data)
    def write_eof(self):
        """Close the write end after flushing buffered data.
        (This is like typing ^D into a UNIX program reading from stdin.)
        Data may still be received.
        """
        raise NotImplementedError
    def can_write_eof(self):
        """Return True if this transport supports write_eof(), False if not."""
        raise NotImplementedError
    def abort(self):
        """Close the transport immediately.
        Buffered data will be lost.  No more data will be received.
        The protocol's connection_lost() method will (eventually) be
        called with None as its argument.
        """
        raise NotImplementedError
 class Transport(ReadTransport, WriteTransport):
    """Interface representing a bidirectional transport.
    There may be several implementations, but typically, the user does
    not implement new transports; rather, the platform provides some
    useful transports that are implemented using the platform's best
    practices.
    The user never instantiates a transport directly; they call a
    utility function, passing it a protocol factory and other
    information necessary to create the transport and protocol.  (E.g.
    EventLoop.create_connection() or EventLoop.create_server().)
    The utility function will asynchronously create a transport and a
    protocol and hook them up by calling the protocol's
    connection_made() method, passing it the transport.
    The implementation here raises NotImplemented for every method
    except writelines(), which calls write() in a loop.
    """
 class DatagramTransport(BaseTransport):
    """Interface for datagram (UDP) transports."""
    def sendto(self, data, addr=None):
        """Send data to the transport.
        This does not block; it buffers the data and arranges for it
        to be sent out asynchronously.
        addr is target socket address.
        If addr is None use target address pointed on transport creation.
        """
        raise NotImplementedError
    def abort(self):
        """Close the transport immediately.
        Buffered data will be lost.  No more data will be received.
        The protocol's connection_lost() method will (eventually) be
        called with None as its argument.
        """
        raise NotImplementedError
 class SubprocessTransport(BaseTransport):
    def get_pid(self):
        """Get subprocess id."""
        raise NotImplementedError
    def get_returncode(self):
        """Get subprocess returncode.
        See also
        http://docs.python.org/3/library/subprocess#subprocess.Popen.returncode
        """
        raise NotImplementedError
    def get_pipe_transport(self, fd):
        """Get transport for pipe with number fd."""
        raise NotImplementedError
    def send_signal(self, signal):
        """Send signal to subprocess.
        See also:
        docs.python.org/3/library/subprocess#subprocess.Popen.send_signal
        """
        raise NotImplementedError
    def terminate(self):
        """Stop the subprocess.
        Alias for close() method.
        On Posix OSs the method sends SIGTERM to the subprocess.
        On Windows the Win32 API function TerminateProcess()
         is called to stop the subprocess.
        See also:
        http://docs.python.org/3/library/subprocess#subprocess.Popen.terminate
        """
        raise NotImplementedError
    def kill(self):
        """Kill the subprocess.
        On Posix OSs the function sends SIGKILL to the subprocess.
        On Windows kill() is an alias for terminate().
        See also:
        http://docs.python.org/3/library/subprocess#subprocess.Popen.kill
        """
        raise NotImplementedError
 class _FlowControlMixin(Transport):
    """All the logic for (write) flow control in a mix-in base class.
    The subclass must implement get_write_buffer_size().  It must call
    _maybe_pause_protocol() whenever the write buffer size increases,
    and _maybe_resume_protocol() whenever it decreases.  It may also
    override set_write_buffer_limits() (e.g. to specify different
    defaults).
    The subclass constructor must call super().__init__(extra).  This
    will call set_write_buffer_limits().
    The user may call set_write_buffer_limits() and
    get_write_buffer_size(), and their protocol's pause_writing() and
    resume_writing() may be called.
    """
    def __init__(self, extra=None, loop=None):
        super().__init__(extra)
        assert loop is not None
        self._loop = loop
        self._protocol_paused = False
        self._set_write_buffer_limits()
    def _maybe_pause_protocol(self):
        size = self.get_write_buffer_size()
        if size <= self._high_water:
            return
        if not self._protocol_paused:
            self._protocol_paused = True
            try:
                self._protocol.pause_writing()
            except Exception as exc:
                self._loop.call_exception_handler({
                    'message': 'protocol.pause_writing() failed',
                    'exception': exc,
                    'transport': self,
                    'protocol': self._protocol,
                })
    def _maybe_resume_protocol(self):
        if (self._protocol_paused and
                self.get_write_buffer_size() <= self._low_water):
            self._protocol_paused = False
            try:
                self._protocol.resume_writing()
            except Exception as exc:
                self._loop.call_exception_handler({
                    'message': 'protocol.resume_writing() failed',
                    'exception': exc,
                    'transport': self,
                    'protocol': self._protocol,
                })
    def get_write_buffer_limits(self):
        return (self._low_water, self._high_water)
    def _set_write_buffer_limits(self, high=None, low=None):
        if high is None:
            if low is None:
                high = 64 * 1024
            else:
                high = 4 * low
        if low is None:
            low = high // 4
        if not high >= low >= 0:
            raise ValueError(
                f'high ({high!r}) must be >= low ({low!r}) must be >= 0')
        self._high_water = high
        self._low_water = low
    def set_write_buffer_limits(self, high=None, low=None):
        self._set_write_buffer_limits(high=high, low=low)
        self._maybe_pause_protocol()
    def get_write_buffer_size(self):
        raise NotImplementedError
--- a/Lib/asyncio/unix_events.py
+++ b/Lib/asyncio/unix_events.py
--- a/Lib/asyncio/windows_events.py
+++ b/Lib/asyncio/windows_events.py
@ -0,0 +1,813 @@
 """Selector and proactor event loops for Windows."""
 import _overlapped
 import _winapi
 import errno
 import math
 import msvcrt
 import socket
 import struct
 import weakref
 from . import events
 from . import base_subprocess
 from . import futures
 from . import proactor_events
 from . import selector_events
 from . import tasks
 from . import windows_utils
 from .log import logger
 __all__ = (
    'SelectorEventLoop', 'ProactorEventLoop', 'IocpProactor',
    'DefaultEventLoopPolicy', 'WindowsSelectorEventLoopPolicy',
    'WindowsProactorEventLoopPolicy',
 )
 NULL = 0
 INFINITE = 0xffffffff
 ERROR_CONNECTION_REFUSED = 1225
 ERROR_CONNECTION_ABORTED = 1236
 # Initial delay in seconds for connect_pipe() before retrying to connect
 CONNECT_PIPE_INIT_DELAY = 0.001
 # Maximum delay in seconds for connect_pipe() before retrying to connect
 CONNECT_PIPE_MAX_DELAY = 0.100
 class _OverlappedFuture(futures.Future):
    """Subclass of Future which represents an overlapped operation.
    Cancelling it will immediately cancel the overlapped operation.
    """
    def __init__(self, ov, *, loop=None):
        super().__init__(loop=loop)
        if self._source_traceback:
            del self._source_traceback[-1]
        self._ov = ov
    def _repr_info(self):
        info = super()._repr_info()
        if self._ov is not None:
            state = 'pending' if self._ov.pending else 'completed'
            info.insert(1, f'overlapped=<{state}, {self._ov.address:#x}>')
        return info
    def _cancel_overlapped(self):
        if self._ov is None:
            return
        try:
            self._ov.cancel()
        except OSError as exc:
            context = {
                'message': 'Cancelling an overlapped future failed',
                'exception': exc,
                'future': self,
            }
            if self._source_traceback:
                context['source_traceback'] = self._source_traceback
            self._loop.call_exception_handler(context)
        self._ov = None
    def cancel(self):
        self._cancel_overlapped()
        return super().cancel()
    def set_exception(self, exception):
        super().set_exception(exception)
        self._cancel_overlapped()
    def set_result(self, result):
        super().set_result(result)
        self._ov = None
 class _BaseWaitHandleFuture(futures.Future):
    """Subclass of Future which represents a wait handle."""
    def __init__(self, ov, handle, wait_handle, *, loop=None):
        super().__init__(loop=loop)
        if self._source_traceback:
            del self._source_traceback[-1]
        # Keep a reference to the Overlapped object to keep it alive until the
        # wait is unregistered
        self._ov = ov
        self._handle = handle
        self._wait_handle = wait_handle
        # Should we call UnregisterWaitEx() if the wait completes
        # or is cancelled?
        self._registered = True
    def _poll(self):
        # non-blocking wait: use a timeout of 0 millisecond
        return (_winapi.WaitForSingleObject(self._handle, 0) ==
                _winapi.WAIT_OBJECT_0)
    def _repr_info(self):
        info = super()._repr_info()
        info.append(f'handle={self._handle:#x}')
        if self._handle is not None:
            state = 'signaled' if self._poll() else 'waiting'
            info.append(state)
        if self._wait_handle is not None:
            info.append(f'wait_handle={self._wait_handle:#x}')
        return info
    def _unregister_wait_cb(self, fut):
        # The wait was unregistered: it's not safe to destroy the Overlapped
        # object
        self._ov = None
    def _unregister_wait(self):
        if not self._registered:
            return
        self._registered = False
        wait_handle = self._wait_handle
        self._wait_handle = None
        try:
            _overlapped.UnregisterWait(wait_handle)
        except OSError as exc:
            if exc.winerror != _overlapped.ERROR_IO_PENDING:
                context = {
                    'message': 'Failed to unregister the wait handle',
                    'exception': exc,
                    'future': self,
                }
                if self._source_traceback:
                    context['source_traceback'] = self._source_traceback
                self._loop.call_exception_handler(context)
                return
            # ERROR_IO_PENDING means that the unregister is pending
        self._unregister_wait_cb(None)
    def cancel(self):
        self._unregister_wait()
        return super().cancel()
    def set_exception(self, exception):
        self._unregister_wait()
        super().set_exception(exception)
    def set_result(self, result):
        self._unregister_wait()
        super().set_result(result)
 class _WaitCancelFuture(_BaseWaitHandleFuture):
    """Subclass of Future which represents a wait for the cancellation of a
    _WaitHandleFuture using an event.
    """
    def __init__(self, ov, event, wait_handle, *, loop=None):
        super().__init__(ov, event, wait_handle, loop=loop)
        self._done_callback = None
    def cancel(self):
        raise RuntimeError("_WaitCancelFuture must not be cancelled")
    def set_result(self, result):
        super().set_result(result)
        if self._done_callback is not None:
            self._done_callback(self)
    def set_exception(self, exception):
        super().set_exception(exception)
        if self._done_callback is not None:
            self._done_callback(self)
 class _WaitHandleFuture(_BaseWaitHandleFuture):
    def __init__(self, ov, handle, wait_handle, proactor, *, loop=None):
        super().__init__(ov, handle, wait_handle, loop=loop)
        self._proactor = proactor
        self._unregister_proactor = True
        self._event = _overlapped.CreateEvent(None, True, False, None)
        self._event_fut = None
    def _unregister_wait_cb(self, fut):
        if self._event is not None:
            _winapi.CloseHandle(self._event)
            self._event = None
            self._event_fut = None
        # If the wait was cancelled, the wait may never be signalled, so
        # it's required to unregister it. Otherwise, IocpProactor.close() will
        # wait forever for an event which will never come.
        #
        # If the IocpProactor already received the event, it's safe to call
        # _unregister() because we kept a reference to the Overlapped object
        # which is used as a unique key.
        self._proactor._unregister(self._ov)
        self._proactor = None
        super()._unregister_wait_cb(fut)
    def _unregister_wait(self):
        if not self._registered:
            return
        self._registered = False
        wait_handle = self._wait_handle
        self._wait_handle = None
        try:
            _overlapped.UnregisterWaitEx(wait_handle, self._event)
        except OSError as exc:
            if exc.winerror != _overlapped.ERROR_IO_PENDING:
                context = {
                    'message': 'Failed to unregister the wait handle',
                    'exception': exc,
                    'future': self,
                }
                if self._source_traceback:
                    context['source_traceback'] = self._source_traceback
                self._loop.call_exception_handler(context)
                return
            # ERROR_IO_PENDING is not an error, the wait was unregistered
        self._event_fut = self._proactor._wait_cancel(self._event,
                                                      self._unregister_wait_cb)
 class PipeServer(object):
    """Class representing a pipe server.
    This is much like a bound, listening socket.
    """
    def __init__(self, address):
        self._address = address
        self._free_instances = weakref.WeakSet()
        # initialize the pipe attribute before calling _server_pipe_handle()
        # because this function can raise an exception and the destructor calls
        # the close() method
        self._pipe = None
        self._accept_pipe_future = None
        self._pipe = self._server_pipe_handle(True)
    def _get_unconnected_pipe(self):
        # Create new instance and return previous one.  This ensures
        # that (until the server is closed) there is always at least
        # one pipe handle for address.  Therefore if a client attempt
        # to connect it will not fail with FileNotFoundError.
        tmp, self._pipe = self._pipe, self._server_pipe_handle(False)
        return tmp
    def _server_pipe_handle(self, first):
        # Return a wrapper for a new pipe handle.
        if self.closed():
            return None
        flags = _winapi.PIPE_ACCESS_DUPLEX | _winapi.FILE_FLAG_OVERLAPPED
        if first:
            flags |= _winapi.FILE_FLAG_FIRST_PIPE_INSTANCE
        h = _winapi.CreateNamedPipe(
            self._address, flags,
            _winapi.PIPE_TYPE_MESSAGE | _winapi.PIPE_READMODE_MESSAGE |
            _winapi.PIPE_WAIT,
            _winapi.PIPE_UNLIMITED_INSTANCES,
            windows_utils.BUFSIZE, windows_utils.BUFSIZE,
            _winapi.NMPWAIT_WAIT_FOREVER, _winapi.NULL)
        pipe = windows_utils.PipeHandle(h)
        self._free_instances.add(pipe)
        return pipe
    def closed(self):
        return (self._address is None)
    def close(self):
        if self._accept_pipe_future is not None:
            self._accept_pipe_future.cancel()
            self._accept_pipe_future = None
        # Close all instances which have not been connected to by a client.
        if self._address is not None:
            for pipe in self._free_instances:
                pipe.close()
            self._pipe = None
            self._address = None
            self._free_instances.clear()
    __del__ = close
 class _WindowsSelectorEventLoop(selector_events.BaseSelectorEventLoop):
    """Windows version of selector event loop."""
 class ProactorEventLoop(proactor_events.BaseProactorEventLoop):
    """Windows version of proactor event loop using IOCP."""
    def __init__(self, proactor=None):
        if proactor is None:
            proactor = IocpProactor()
        super().__init__(proactor)
    async def create_pipe_connection(self, protocol_factory, address):
        f = self._proactor.connect_pipe(address)
        pipe = await f
        protocol = protocol_factory()
        trans = self._make_duplex_pipe_transport(pipe, protocol,
                                                 extra={'addr': address})
        return trans, protocol
    async def start_serving_pipe(self, protocol_factory, address):
        server = PipeServer(address)
        def loop_accept_pipe(f=None):
            pipe = None
            try:
                if f:
                    pipe = f.result()
                    server._free_instances.discard(pipe)
                    if server.closed():
                        # A client connected before the server was closed:
                        # drop the client (close the pipe) and exit
                        pipe.close()
                        return
                    protocol = protocol_factory()
                    self._make_duplex_pipe_transport(
                        pipe, protocol, extra={'addr': address})
                pipe = server._get_unconnected_pipe()
                if pipe is None:
                    return
                f = self._proactor.accept_pipe(pipe)
            except OSError as exc:
                if pipe and pipe.fileno() != -1:
                    self.call_exception_handler({
                        'message': 'Pipe accept failed',
                        'exception': exc,
                        'pipe': pipe,
                    })
                    pipe.close()
                elif self._debug:
                    logger.warning("Accept pipe failed on pipe %r",
                                   pipe, exc_info=True)
            except futures.CancelledError:
                if pipe:
                    pipe.close()
            else:
                server._accept_pipe_future = f
                f.add_done_callback(loop_accept_pipe)
        self.call_soon(loop_accept_pipe)
        return [server]
    async def _make_subprocess_transport(self, protocol, args, shell,
                                         stdin, stdout, stderr, bufsize,
                                         extra=None, **kwargs):
        waiter = self.create_future()
        transp = _WindowsSubprocessTransport(self, protocol, args, shell,
                                             stdin, stdout, stderr, bufsize,
                                             waiter=waiter, extra=extra,
                                             **kwargs)
        try:
            await waiter
        except Exception:
            transp.close()
            await transp._wait()
            raise
        return transp
 class IocpProactor:
    """Proactor implementation using IOCP."""
    def __init__(self, concurrency=0xffffffff):
        self._loop = None
        self._results = []
        self._iocp = _overlapped.CreateIoCompletionPort(
            _overlapped.INVALID_HANDLE_VALUE, NULL, 0, concurrency)
        self._cache = {}
        self._registered = weakref.WeakSet()
        self._unregistered = []
        self._stopped_serving = weakref.WeakSet()
    def __repr__(self):
        return ('<%s overlapped#=%s result#=%s>'
                % (self.__class__.__name__, len(self._cache),
                   len(self._results)))
    def set_loop(self, loop):
        self._loop = loop
    def select(self, timeout=None):
        if not self._results:
            self._poll(timeout)
        tmp = self._results
        self._results = []
        return tmp
    def _result(self, value):
        fut = self._loop.create_future()
        fut.set_result(value)
        return fut
    def recv(self, conn, nbytes, flags=0):
        self._register_with_iocp(conn)
        ov = _overlapped.Overlapped(NULL)
        try:
            if isinstance(conn, socket.socket):
                ov.WSARecv(conn.fileno(), nbytes, flags)
            else:
                ov.ReadFile(conn.fileno(), nbytes)
        except BrokenPipeError:
            return self._result(b'')
        def finish_recv(trans, key, ov):
            try:
                return ov.getresult()
            except OSError as exc:
                if exc.winerror in (_overlapped.ERROR_NETNAME_DELETED,
                                    _overlapped.ERROR_OPERATION_ABORTED):
                    raise ConnectionResetError(*exc.args)
                else:
                    raise
        return self._register(ov, conn, finish_recv)
    def recv_into(self, conn, buf, flags=0):
        self._register_with_iocp(conn)
        ov = _overlapped.Overlapped(NULL)
        try:
            if isinstance(conn, socket.socket):
                ov.WSARecvInto(conn.fileno(), buf, flags)
            else:
                ov.ReadFileInto(conn.fileno(), buf)
        except BrokenPipeError:
            return self._result(b'')
        def finish_recv(trans, key, ov):
            try:
                return ov.getresult()
            except OSError as exc:
                if exc.winerror in (_overlapped.ERROR_NETNAME_DELETED,
                                    _overlapped.ERROR_OPERATION_ABORTED):
                    raise ConnectionResetError(*exc.args)
                else:
                    raise
        return self._register(ov, conn, finish_recv)
    def send(self, conn, buf, flags=0):
        self._register_with_iocp(conn)
        ov = _overlapped.Overlapped(NULL)
        if isinstance(conn, socket.socket):
            ov.WSASend(conn.fileno(), buf, flags)
        else:
            ov.WriteFile(conn.fileno(), buf)
        def finish_send(trans, key, ov):
            try:
                return ov.getresult()
            except OSError as exc:
                if exc.winerror in (_overlapped.ERROR_NETNAME_DELETED,
                                    _overlapped.ERROR_OPERATION_ABORTED):
                    raise ConnectionResetError(*exc.args)
                else:
                    raise
        return self._register(ov, conn, finish_send)
    def accept(self, listener):
        self._register_with_iocp(listener)
        conn = self._get_accept_socket(listener.family)
        ov = _overlapped.Overlapped(NULL)
        ov.AcceptEx(listener.fileno(), conn.fileno())
        def finish_accept(trans, key, ov):
            ov.getresult()
            # Use SO_UPDATE_ACCEPT_CONTEXT so getsockname() etc work.
            buf = struct.pack('@P', listener.fileno())
            conn.setsockopt(socket.SOL_SOCKET,
                            _overlapped.SO_UPDATE_ACCEPT_CONTEXT, buf)
            conn.settimeout(listener.gettimeout())
            return conn, conn.getpeername()
        async def accept_coro(future, conn):
            # Coroutine closing the accept socket if the future is cancelled
            try:
                await future
            except futures.CancelledError:
                conn.close()
                raise
        future = self._register(ov, listener, finish_accept)
        coro = accept_coro(future, conn)
        tasks.ensure_future(coro, loop=self._loop)
        return future
    def connect(self, conn, address):
        self._register_with_iocp(conn)
        # The socket needs to be locally bound before we call ConnectEx().
        try:
            _overlapped.BindLocal(conn.fileno(), conn.family)
        except OSError as e:
            if e.winerror != errno.WSAEINVAL:
                raise
            # Probably already locally bound; check using getsockname().
            if conn.getsockname()[1] == 0:
                raise
        ov = _overlapped.Overlapped(NULL)
        ov.ConnectEx(conn.fileno(), address)
        def finish_connect(trans, key, ov):
            ov.getresult()
            # Use SO_UPDATE_CONNECT_CONTEXT so getsockname() etc work.
            conn.setsockopt(socket.SOL_SOCKET,
                            _overlapped.SO_UPDATE_CONNECT_CONTEXT, 0)
            return conn
        return self._register(ov, conn, finish_connect)
    def sendfile(self, sock, file, offset, count):
        self._register_with_iocp(sock)
        ov = _overlapped.Overlapped(NULL)
        offset_low = offset & 0xffff_ffff
        offset_high = (offset >> 32) & 0xffff_ffff
        ov.TransmitFile(sock.fileno(),
                        msvcrt.get_osfhandle(file.fileno()),
                        offset_low, offset_high,
                        count, 0, 0)
        def finish_sendfile(trans, key, ov):
            try:
                return ov.getresult()
            except OSError as exc:
                if exc.winerror in (_overlapped.ERROR_NETNAME_DELETED,
                                    _overlapped.ERROR_OPERATION_ABORTED):
                    raise ConnectionResetError(*exc.args)
                else:
                    raise
        return self._register(ov, sock, finish_sendfile)
    def accept_pipe(self, pipe):
        self._register_with_iocp(pipe)
        ov = _overlapped.Overlapped(NULL)
        connected = ov.ConnectNamedPipe(pipe.fileno())
        if connected:
            # ConnectNamePipe() failed with ERROR_PIPE_CONNECTED which means
            # that the pipe is connected. There is no need to wait for the
            # completion of the connection.
            return self._result(pipe)
        def finish_accept_pipe(trans, key, ov):
            ov.getresult()
            return pipe
        return self._register(ov, pipe, finish_accept_pipe)
    async def connect_pipe(self, address):
        delay = CONNECT_PIPE_INIT_DELAY
        while True:
            # Unfortunately there is no way to do an overlapped connect to
            # a pipe.  Call CreateFile() in a loop until it doesn't fail with
            # ERROR_PIPE_BUSY.
            try:
                handle = _overlapped.ConnectPipe(address)
                break
            except OSError as exc:
                if exc.winerror != _overlapped.ERROR_PIPE_BUSY:
                    raise
            # ConnectPipe() failed with ERROR_PIPE_BUSY: retry later
            delay = min(delay * 2, CONNECT_PIPE_MAX_DELAY)
            await tasks.sleep(delay, loop=self._loop)
        return windows_utils.PipeHandle(handle)
    def wait_for_handle(self, handle, timeout=None):
        """Wait for a handle.
        Return a Future object. The result of the future is True if the wait
        completed, or False if the wait did not complete (on timeout).
        """
        return self._wait_for_handle(handle, timeout, False)
    def _wait_cancel(self, event, done_callback):
        fut = self._wait_for_handle(event, None, True)
        # add_done_callback() cannot be used because the wait may only complete
        # in IocpProactor.close(), while the event loop is not running.
        fut._done_callback = done_callback
        return fut
    def _wait_for_handle(self, handle, timeout, _is_cancel):
        if timeout is None:
            ms = _winapi.INFINITE
        else:
            # RegisterWaitForSingleObject() has a resolution of 1 millisecond,
            # round away from zero to wait *at least* timeout seconds.
            ms = math.ceil(timeout * 1e3)
        # We only create ov so we can use ov.address as a key for the cache.
        ov = _overlapped.Overlapped(NULL)
        wait_handle = _overlapped.RegisterWaitWithQueue(
            handle, self._iocp, ov.address, ms)
        if _is_cancel:
            f = _WaitCancelFuture(ov, handle, wait_handle, loop=self._loop)
        else:
            f = _WaitHandleFuture(ov, handle, wait_handle, self,
                                  loop=self._loop)
        if f._source_traceback:
            del f._source_traceback[-1]
        def finish_wait_for_handle(trans, key, ov):
            # Note that this second wait means that we should only use
            # this with handles types where a successful wait has no
            # effect.  So events or processes are all right, but locks
            # or semaphores are not.  Also note if the handle is
            # signalled and then quickly reset, then we may return
            # False even though we have not timed out.
            return f._poll()
        self._cache[ov.address] = (f, ov, 0, finish_wait_for_handle)
        return f
    def _register_with_iocp(self, obj):
        # To get notifications of finished ops on this objects sent to the
        # completion port, were must register the handle.
        if obj not in self._registered:
            self._registered.add(obj)
            _overlapped.CreateIoCompletionPort(obj.fileno(), self._iocp, 0, 0)
            # XXX We could also use SetFileCompletionNotificationModes()
            # to avoid sending notifications to completion port of ops
            # that succeed immediately.
    def _register(self, ov, obj, callback):
        # Return a future which will be set with the result of the
        # operation when it completes.  The future's value is actually
        # the value returned by callback().
        f = _OverlappedFuture(ov, loop=self._loop)
        if f._source_traceback:
            del f._source_traceback[-1]
        if not ov.pending:
            # The operation has completed, so no need to postpone the
            # work.  We cannot take this short cut if we need the
            # NumberOfBytes, CompletionKey values returned by
            # PostQueuedCompletionStatus().
            try:
                value = callback(None, None, ov)
            except OSError as e:
                f.set_exception(e)
            else:
                f.set_result(value)
            # Even if GetOverlappedResult() was called, we have to wait for the
            # notification of the completion in GetQueuedCompletionStatus().
            # Register the overlapped operation to keep a reference to the
            # OVERLAPPED object, otherwise the memory is freed and Windows may
            # read uninitialized memory.
        # Register the overlapped operation for later.  Note that
        # we only store obj to prevent it from being garbage
        # collected too early.
        self._cache[ov.address] = (f, ov, obj, callback)
        return f
    def _unregister(self, ov):
        """Unregister an overlapped object.
        Call this method when its future has been cancelled. The event can
        already be signalled (pending in the proactor event queue). It is also
        safe if the event is never signalled (because it was cancelled).
        """
        self._unregistered.append(ov)
    def _get_accept_socket(self, family):
        s = socket.socket(family)
        s.settimeout(0)
        return s
    def _poll(self, timeout=None):
        if timeout is None:
            ms = INFINITE
        elif timeout < 0:
            raise ValueError("negative timeout")
        else:
            # GetQueuedCompletionStatus() has a resolution of 1 millisecond,
            # round away from zero to wait *at least* timeout seconds.
            ms = math.ceil(timeout * 1e3)
            if ms >= INFINITE:
                raise ValueError("timeout too big")
        while True:
            status = _overlapped.GetQueuedCompletionStatus(self._iocp, ms)
            if status is None:
                break
            ms = 0
            err, transferred, key, address = status
            try:
                f, ov, obj, callback = self._cache.pop(address)
            except KeyError:
                if self._loop.get_debug():
                    self._loop.call_exception_handler({
                        'message': ('GetQueuedCompletionStatus() returned an '
                                    'unexpected event'),
                        'status': ('err=%s transferred=%s key=%#x address=%#x'
                                   % (err, transferred, key, address)),
                    })
                # key is either zero, or it is used to return a pipe
                # handle which should be closed to avoid a leak.
                if key not in (0, _overlapped.INVALID_HANDLE_VALUE):
                    _winapi.CloseHandle(key)
                continue
            if obj in self._stopped_serving:
                f.cancel()
            # Don't call the callback if _register() already read the result or
            # if the overlapped has been cancelled
            elif not f.done():
                try:
                    value = callback(transferred, key, ov)
                except OSError as e:
                    f.set_exception(e)
                    self._results.append(f)
                else:
                    f.set_result(value)
                    self._results.append(f)
        # Remove unregistered futures
        for ov in self._unregistered:
            self._cache.pop(ov.address, None)
        self._unregistered.clear()
    def _stop_serving(self, obj):
        # obj is a socket or pipe handle.  It will be closed in
        # BaseProactorEventLoop._stop_serving() which will make any
        # pending operations fail quickly.
        self._stopped_serving.add(obj)
    def close(self):
        # Cancel remaining registered operations.
        for address, (fut, ov, obj, callback) in list(self._cache.items()):
            if fut.cancelled():
                # Nothing to do with cancelled futures
                pass
            elif isinstance(fut, _WaitCancelFuture):
                # _WaitCancelFuture must not be cancelled
                pass
            else:
                try:
                    fut.cancel()
                except OSError as exc:
                    if self._loop is not None:
                        context = {
                            'message': 'Cancelling a future failed',
                            'exception': exc,
                            'future': fut,
                        }
                        if fut._source_traceback:
                            context['source_traceback'] = fut._source_traceback
                        self._loop.call_exception_handler(context)
        while self._cache:
            if not self._poll(1):
                logger.debug('taking long time to close proactor')
        self._results = []
        if self._iocp is not None:
            _winapi.CloseHandle(self._iocp)
            self._iocp = None
    def __del__(self):
        self.close()
 class _WindowsSubprocessTransport(base_subprocess.BaseSubprocessTransport):
    def _start(self, args, shell, stdin, stdout, stderr, bufsize, **kwargs):
        self._proc = windows_utils.Popen(
            args, shell=shell, stdin=stdin, stdout=stdout, stderr=stderr,
            bufsize=bufsize, **kwargs)
        def callback(f):
            returncode = self._proc.poll()
            self._process_exited(returncode)
        f = self._loop._proactor.wait_for_handle(int(self._proc._handle))
        f.add_done_callback(callback)
 SelectorEventLoop = _WindowsSelectorEventLoop
 class WindowsSelectorEventLoopPolicy(events.BaseDefaultEventLoopPolicy):
    _loop_factory = SelectorEventLoop
 class WindowsProactorEventLoopPolicy(events.BaseDefaultEventLoopPolicy):
    _loop_factory = ProactorEventLoop
 DefaultEventLoopPolicy = WindowsSelectorEventLoopPolicy
--- a/Lib/asyncio/windows_utils.py
+++ b/Lib/asyncio/windows_utils.py
@ -0,0 +1,174 @@
 """Various Windows specific bits and pieces."""
 import sys
 if sys.platform != 'win32':  # pragma: no cover
    raise ImportError('win32 only')
 import _winapi
 import itertools
 import msvcrt
 import os
 import subprocess
 import tempfile
 import warnings
 __all__ = 'pipe', 'Popen', 'PIPE', 'PipeHandle'
 # Constants/globals
 BUFSIZE = 8192
 PIPE = subprocess.PIPE
 STDOUT = subprocess.STDOUT
 _mmap_counter = itertools.count()
 # Replacement for os.pipe() using handles instead of fds
 def pipe(*, duplex=False, overlapped=(True, True), bufsize=BUFSIZE):
    """Like os.pipe() but with overlapped support and using handles not fds."""
    address = tempfile.mktemp(
        prefix=r'\\.\pipe\python-pipe-{:d}-{:d}-'.format(
            os.getpid(), next(_mmap_counter)))
    if duplex:
        openmode = _winapi.PIPE_ACCESS_DUPLEX
        access = _winapi.GENERIC_READ | _winapi.GENERIC_WRITE
        obsize, ibsize = bufsize, bufsize
    else:
        openmode = _winapi.PIPE_ACCESS_INBOUND
        access = _winapi.GENERIC_WRITE
        obsize, ibsize = 0, bufsize
    openmode |= _winapi.FILE_FLAG_FIRST_PIPE_INSTANCE
    if overlapped[0]:
        openmode |= _winapi.FILE_FLAG_OVERLAPPED
    if overlapped[1]:
        flags_and_attribs = _winapi.FILE_FLAG_OVERLAPPED
    else:
        flags_and_attribs = 0
    h1 = h2 = None
    try:
        h1 = _winapi.CreateNamedPipe(
            address, openmode, _winapi.PIPE_WAIT,
            1, obsize, ibsize, _winapi.NMPWAIT_WAIT_FOREVER, _winapi.NULL)
        h2 = _winapi.CreateFile(
            address, access, 0, _winapi.NULL, _winapi.OPEN_EXISTING,
            flags_and_attribs, _winapi.NULL)
        ov = _winapi.ConnectNamedPipe(h1, overlapped=True)
        ov.GetOverlappedResult(True)
        return h1, h2
    except:
        if h1 is not None:
            _winapi.CloseHandle(h1)
        if h2 is not None:
            _winapi.CloseHandle(h2)
        raise
 # Wrapper for a pipe handle
 class PipeHandle:
    """Wrapper for an overlapped pipe handle which is vaguely file-object like.
    The IOCP event loop can use these instead of socket objects.
    """
    def __init__(self, handle):
        self._handle = handle
    def __repr__(self):
        if self._handle is not None:
            handle = f'handle={self._handle!r}'
        else:
            handle = 'closed'
        return f'<{self.__class__.__name__} {handle}>'
    @property
    def handle(self):
        return self._handle
    def fileno(self):
        if self._handle is None:
            raise ValueError("I/O operation on closed pipe")
        return self._handle
    def close(self, *, CloseHandle=_winapi.CloseHandle):
        if self._handle is not None:
            CloseHandle(self._handle)
            self._handle = None
    def __del__(self):
        if self._handle is not None:
            warnings.warn(f"unclosed {self!r}", ResourceWarning,
                          source=self)
            self.close()
    def __enter__(self):
        return self
    def __exit__(self, t, v, tb):
        self.close()
 # Replacement for subprocess.Popen using overlapped pipe handles
 class Popen(subprocess.Popen):
    """Replacement for subprocess.Popen using overlapped pipe handles.
    The stdin, stdout, stderr are None or instances of PipeHandle.
    """
    def __init__(self, args, stdin=None, stdout=None, stderr=None, **kwds):
        assert not kwds.get('universal_newlines')
        assert kwds.get('bufsize', 0) == 0
        stdin_rfd = stdout_wfd = stderr_wfd = None
        stdin_wh = stdout_rh = stderr_rh = None
        if stdin == PIPE:
            stdin_rh, stdin_wh = pipe(overlapped=(False, True), duplex=True)
            stdin_rfd = msvcrt.open_osfhandle(stdin_rh, os.O_RDONLY)
        else:
            stdin_rfd = stdin
        if stdout == PIPE:
            stdout_rh, stdout_wh = pipe(overlapped=(True, False))
            stdout_wfd = msvcrt.open_osfhandle(stdout_wh, 0)
        else:
            stdout_wfd = stdout
        if stderr == PIPE:
            stderr_rh, stderr_wh = pipe(overlapped=(True, False))
            stderr_wfd = msvcrt.open_osfhandle(stderr_wh, 0)
        elif stderr == STDOUT:
            stderr_wfd = stdout_wfd
        else:
            stderr_wfd = stderr
        try:
            super().__init__(args, stdin=stdin_rfd, stdout=stdout_wfd,
                             stderr=stderr_wfd, **kwds)
        except:
            for h in (stdin_wh, stdout_rh, stderr_rh):
                if h is not None:
                    _winapi.CloseHandle(h)
            raise
        else:
            if stdin_wh is not None:
                self.stdin = PipeHandle(stdin_wh)
            if stdout_rh is not None:
                self.stdout = PipeHandle(stdout_rh)
            if stderr_rh is not None:
                self.stderr = PipeHandle(stderr_rh)
        finally:
            if stdin == PIPE:
                os.close(stdin_rfd)
            if stdout == PIPE:
                os.close(stdout_wfd)
            if stderr == PIPE:
                os.close(stderr_wfd)
--- a/Lib/asyncore.py
+++ b/Lib/asyncore.py
@ -0,0 +1,644 @@
 # -*- Mode: Python -*-
 #   Id: asyncore.py,v 2.51 2000/09/07 22:29:26 rushing Exp
 #   Author: Sam Rushing <rushing@nightmare.com>
 # ======================================================================
 # Copyright 1996 by Sam Rushing
 #
 #                         All Rights Reserved
 #
 # Permission to use, copy, modify, and distribute this software and
 # its documentation for any purpose and without fee is hereby
 # granted, provided that the above copyright notice appear in all
 # copies and that both that copyright notice and this permission
 # notice appear in supporting documentation, and that the name of Sam
 # Rushing not be used in advertising or publicity pertaining to
 # distribution of the software without specific, written prior
 # permission.
 #
 # SAM RUSHING DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 # INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
 # NO EVENT SHALL SAM RUSHING BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 # CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
 # OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 # NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 # CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 # ======================================================================
 """Basic infrastructure for asynchronous socket service clients and servers.
 There are only two ways to have a program on a single processor do "more
 than one thing at a time".  Multi-threaded programming is the simplest and
 most popular way to do it, but there is another very different technique,
 that lets you have nearly all the advantages of multi-threading, without
 actually using multiple threads. it's really only practical if your program
 is largely I/O bound. If your program is CPU bound, then pre-emptive
 scheduled threads are probably what you really need. Network servers are
 rarely CPU-bound, however.
 If your operating system supports the select() system call in its I/O
 library (and nearly all do), then you can use it to juggle multiple
 communication channels at once; doing other work while your I/O is taking
 place in the "background."  Although this strategy can seem strange and
 complex, especially at first, it is in many ways easier to understand and
 control than multi-threaded programming. The module documented here solves
 many of the difficult problems for you, making the task of building
 sophisticated high-performance network servers and clients a snap.
 """
 import select
 import socket
 import sys
 import time
 import warnings
 import os
 from errno import EALREADY, EINPROGRESS, EWOULDBLOCK, ECONNRESET, EINVAL, \
     ENOTCONN, ESHUTDOWN, EISCONN, EBADF, ECONNABORTED, EPIPE, EAGAIN, \
     errorcode
 _DISCONNECTED = frozenset({ECONNRESET, ENOTCONN, ESHUTDOWN, ECONNABORTED, EPIPE,
                           EBADF})
 try:
    socket_map
 except NameError:
    socket_map = {}
 def _strerror(err):
    try:
        return os.strerror(err)
    except (ValueError, OverflowError, NameError):
        if err in errorcode:
            return errorcode[err]
        return "Unknown error %s" %err
 class ExitNow(Exception):
    pass
 _reraised_exceptions = (ExitNow, KeyboardInterrupt, SystemExit)
 def read(obj):
    try:
        obj.handle_read_event()
    except _reraised_exceptions:
        raise
    except:
        obj.handle_error()
 def write(obj):
    try:
        obj.handle_write_event()
    except _reraised_exceptions:
        raise
    except:
        obj.handle_error()
 def _exception(obj):
    try:
        obj.handle_expt_event()
    except _reraised_exceptions:
        raise
    except:
        obj.handle_error()
 def readwrite(obj, flags):
    try:
        if flags & select.POLLIN:
            obj.handle_read_event()
        if flags & select.POLLOUT:
            obj.handle_write_event()
        if flags & select.POLLPRI:
            obj.handle_expt_event()
        if flags & (select.POLLHUP | select.POLLERR | select.POLLNVAL):
            obj.handle_close()
    except OSError as e:
        if e.args[0] not in _DISCONNECTED:
            obj.handle_error()
        else:
            obj.handle_close()
    except _reraised_exceptions:
        raise
    except:
        obj.handle_error()
 def poll(timeout=0.0, map=None):
    if map is None:
        map = socket_map
    if map:
        r = []; w = []; e = []
        for fd, obj in list(map.items()):
            is_r = obj.readable()
            is_w = obj.writable()
            if is_r:
                r.append(fd)
            # accepting sockets should not be writable
            if is_w and not obj.accepting:
                w.append(fd)
            if is_r or is_w:
                e.append(fd)
        if [] == r == w == e:
            time.sleep(timeout)
            return
        r, w, e = select.select(r, w, e, timeout)
        for fd in r:
            obj = map.get(fd)
            if obj is None:
                continue
            read(obj)
        for fd in w:
            obj = map.get(fd)
            if obj is None:
                continue
            write(obj)
        for fd in e:
            obj = map.get(fd)
            if obj is None:
                continue
            _exception(obj)
 def poll2(timeout=0.0, map=None):
    # Use the poll() support added to the select module in Python 2.0
    if map is None:
        map = socket_map
    if timeout is not None:
        # timeout is in milliseconds
        timeout = int(timeout*1000)
    pollster = select.poll()
    if map:
        for fd, obj in list(map.items()):
            flags = 0
            if obj.readable():
                flags |= select.POLLIN | select.POLLPRI
            # accepting sockets should not be writable
            if obj.writable() and not obj.accepting:
                flags |= select.POLLOUT
            if flags:
                pollster.register(fd, flags)
        r = pollster.poll(timeout)
        for fd, flags in r:
            obj = map.get(fd)
            if obj is None:
                continue
            readwrite(obj, flags)
 poll3 = poll2                           # Alias for backward compatibility
 def loop(timeout=30.0, use_poll=False, map=None, count=None):
    if map is None:
        map = socket_map
    if use_poll and hasattr(select, 'poll'):
        poll_fun = poll2
    else:
        poll_fun = poll
    if count is None:
        while map:
            poll_fun(timeout, map)
    else:
        while map and count > 0:
            poll_fun(timeout, map)
            count = count - 1
 class dispatcher:
    debug = False
    connected = False
    accepting = False
    connecting = False
    closing = False
    addr = None
    ignore_log_types = frozenset({'warning'})
    def __init__(self, sock=None, map=None):
        if map is None:
            self._map = socket_map
        else:
            self._map = map
        self._fileno = None
        if sock:
            # Set to nonblocking just to make sure for cases where we
            # get a socket from a blocking source.
            sock.setblocking(0)
            self.set_socket(sock, map)
            self.connected = True
            # The constructor no longer requires that the socket
            # passed be connected.
            try:
                self.addr = sock.getpeername()
            except OSError as err:
                if err.args[0] in (ENOTCONN, EINVAL):
                    # To handle the case where we got an unconnected
                    # socket.
                    self.connected = False
                else:
                    # The socket is broken in some unknown way, alert
                    # the user and remove it from the map (to prevent
                    # polling of broken sockets).
                    self.del_channel(map)
                    raise
        else:
            self.socket = None
    def __repr__(self):
        status = [self.__class__.__module__+"."+self.__class__.__qualname__]
        if self.accepting and self.addr:
            status.append('listening')
        elif self.connected:
            status.append('connected')
        if self.addr is not None:
            try:
                status.append('%s:%d' % self.addr)
            except TypeError:
                status.append(repr(self.addr))
        return '<%s at %#x>' % (' '.join(status), id(self))
    __str__ = __repr__
    def add_channel(self, map=None):
        #self.log_info('adding channel %s' % self)
        if map is None:
            map = self._map
        map[self._fileno] = self
    def del_channel(self, map=None):
        fd = self._fileno
        if map is None:
            map = self._map
        if fd in map:
            #self.log_info('closing channel %d:%s' % (fd, self))
            del map[fd]
        self._fileno = None
    def create_socket(self, family=socket.AF_INET, type=socket.SOCK_STREAM):
        self.family_and_type = family, type
        sock = socket.socket(family, type)
        sock.setblocking(0)
        self.set_socket(sock)
    def set_socket(self, sock, map=None):
        self.socket = sock
        self._fileno = sock.fileno()
        self.add_channel(map)
    def set_reuse_addr(self):
        # try to re-use a server port if possible
        try:
            self.socket.setsockopt(
                socket.SOL_SOCKET, socket.SO_REUSEADDR,
                self.socket.getsockopt(socket.SOL_SOCKET,
                                       socket.SO_REUSEADDR) | 1
                )
        except OSError:
            pass
    # ==================================================
    # predicates for select()
    # these are used as filters for the lists of sockets
    # to pass to select().
    # ==================================================
    def readable(self):
        return True
    def writable(self):
        return True
    # ==================================================
    # socket object methods.
    # ==================================================
    def listen(self, num):
        self.accepting = True
        if os.name == 'nt' and num > 5:
            num = 5
        return self.socket.listen(num)
    def bind(self, addr):
        self.addr = addr
        return self.socket.bind(addr)
    def connect(self, address):
        self.connected = False
        self.connecting = True
        err = self.socket.connect_ex(address)
        if err in (EINPROGRESS, EALREADY, EWOULDBLOCK) \
        or err == EINVAL and os.name == 'nt':
            self.addr = address
            return
        if err in (0, EISCONN):
            self.addr = address
            self.handle_connect_event()
        else:
            raise OSError(err, errorcode[err])
    def accept(self):
        # XXX can return either an address pair or None
        try:
            conn, addr = self.socket.accept()
        except TypeError:
            return None
        except OSError as why:
            if why.args[0] in (EWOULDBLOCK, ECONNABORTED, EAGAIN):
                return None
            else:
                raise
        else:
            return conn, addr
    def send(self, data):
        try:
            result = self.socket.send(data)
            return result
        except OSError as why:
            if why.args[0] == EWOULDBLOCK:
                return 0
            elif why.args[0] in _DISCONNECTED:
                self.handle_close()
                return 0
            else:
                raise
    def recv(self, buffer_size):
        try:
            data = self.socket.recv(buffer_size)
            if not data:
                # a closed connection is indicated by signaling
                # a read condition, and having recv() return 0.
                self.handle_close()
                return b''
            else:
                return data
        except OSError as why:
            # winsock sometimes raises ENOTCONN
            if why.args[0] in _DISCONNECTED:
                self.handle_close()
                return b''
            else:
                raise
    def close(self):
        self.connected = False
        self.accepting = False
        self.connecting = False
        self.del_channel()
        if self.socket is not None:
            try:
                self.socket.close()
            except OSError as why:
                if why.args[0] not in (ENOTCONN, EBADF):
                    raise
    # log and log_info may be overridden to provide more sophisticated
    # logging and warning methods. In general, log is for 'hit' logging
    # and 'log_info' is for informational, warning and error logging.
    def log(self, message):
        sys.stderr.write('log: %s\n' % str(message))
    def log_info(self, message, type='info'):
        if type not in self.ignore_log_types:
            print('%s: %s' % (type, message))
    def handle_read_event(self):
        if self.accepting:
            # accepting sockets are never connected, they "spawn" new
            # sockets that are connected
            self.handle_accept()
        elif not self.connected:
            if self.connecting:
                self.handle_connect_event()
            self.handle_read()
        else:
            self.handle_read()
    def handle_connect_event(self):
        err = self.socket.getsockopt(socket.SOL_SOCKET, socket.SO_ERROR)
        if err != 0:
            raise OSError(err, _strerror(err))
        self.handle_connect()
        self.connected = True
        self.connecting = False
    def handle_write_event(self):
        if self.accepting:
            # Accepting sockets shouldn't get a write event.
            # We will pretend it didn't happen.
            return
        if not self.connected:
            if self.connecting:
                self.handle_connect_event()
        self.handle_write()
    def handle_expt_event(self):
        # handle_expt_event() is called if there might be an error on the
        # socket, or if there is OOB data
        # check for the error condition first
        err = self.socket.getsockopt(socket.SOL_SOCKET, socket.SO_ERROR)
        if err != 0:
            # we can get here when select.select() says that there is an
            # exceptional condition on the socket
            # since there is an error, we'll go ahead and close the socket
            # like we would in a subclassed handle_read() that received no
            # data
            self.handle_close()
        else:
            self.handle_expt()
    def handle_error(self):
        nil, t, v, tbinfo = compact_traceback()
        # sometimes a user repr method will crash.
        try:
            self_repr = repr(self)
        except:
            self_repr = '<__repr__(self) failed for object at %0x>' % id(self)
        self.log_info(
            'uncaptured python exception, closing channel %s (%s:%s %s)' % (
                self_repr,
                t,
                v,
                tbinfo
                ),
            'error'
            )
        self.handle_close()
    def handle_expt(self):
        self.log_info('unhandled incoming priority event', 'warning')
    def handle_read(self):
        self.log_info('unhandled read event', 'warning')
    def handle_write(self):
        self.log_info('unhandled write event', 'warning')
    def handle_connect(self):
        self.log_info('unhandled connect event', 'warning')
    def handle_accept(self):
        pair = self.accept()
        if pair is not None:
            self.handle_accepted(*pair)
    def handle_accepted(self, sock, addr):
        sock.close()
        self.log_info('unhandled accepted event', 'warning')
    def handle_close(self):
        self.log_info('unhandled close event', 'warning')
        self.close()
 # ---------------------------------------------------------------------------
 # adds simple buffered output capability, useful for simple clients.
 # [for more sophisticated usage use asynchat.async_chat]
 # ---------------------------------------------------------------------------
 class dispatcher_with_send(dispatcher):
    def __init__(self, sock=None, map=None):
        dispatcher.__init__(self, sock, map)
        self.out_buffer = b''
    def initiate_send(self):
        num_sent = 0
        num_sent = dispatcher.send(self, self.out_buffer[:65536])
        self.out_buffer = self.out_buffer[num_sent:]
    def handle_write(self):
        self.initiate_send()
    def writable(self):
        return (not self.connected) or len(self.out_buffer)
    def send(self, data):
        if self.debug:
            self.log_info('sending %s' % repr(data))
        self.out_buffer = self.out_buffer + data
        self.initiate_send()
 # ---------------------------------------------------------------------------
 # used for debugging.
 # ---------------------------------------------------------------------------
 def compact_traceback():
    t, v, tb = sys.exc_info()
    tbinfo = []
    if not tb: # Must have a traceback
        raise AssertionError("traceback does not exist")
    while tb:
        tbinfo.append((
            tb.tb_frame.f_code.co_filename,
            tb.tb_frame.f_code.co_name,
            str(tb.tb_lineno)
            ))
        tb = tb.tb_next
    # just to be safe
    del tb
    file, function, line = tbinfo[-1]
    info = ' '.join(['[%s|%s|%s]' % x for x in tbinfo])
    return (file, function, line), t, v, info
 def close_all(map=None, ignore_all=False):
    if map is None:
        map = socket_map
    for x in list(map.values()):
        try:
            x.close()
        except OSError as x:
            if x.args[0] == EBADF:
                pass
            elif not ignore_all:
                raise
        except _reraised_exceptions:
            raise
        except:
            if not ignore_all:
                raise
    map.clear()
 # Asynchronous File I/O:
 #
 # After a little research (reading man pages on various unixen, and
 # digging through the linux kernel), I've determined that select()
 # isn't meant for doing asynchronous file i/o.
 # Heartening, though - reading linux/mm/filemap.c shows that linux
 # supports asynchronous read-ahead.  So _MOST_ of the time, the data
 # will be sitting in memory for us already when we go to read it.
 #
 # What other OS's (besides NT) support async file i/o?  [VMS?]
 #
 # Regardless, this is useful for pipes, and stdin/stdout...
 if os.name == 'posix':
    class file_wrapper:
        # Here we override just enough to make a file
        # look like a socket for the purposes of asyncore.
        # The passed fd is automatically os.dup()'d
        def __init__(self, fd):
            self.fd = os.dup(fd)
        def __del__(self):
            if self.fd >= 0:
                warnings.warn("unclosed file %r" % self, ResourceWarning,
                              source=self)
            self.close()
        def recv(self, *args):
            return os.read(self.fd, *args)
        def send(self, *args):
            return os.write(self.fd, *args)
        def getsockopt(self, level, optname, buflen=None):
            if (level == socket.SOL_SOCKET and
                optname == socket.SO_ERROR and
                not buflen):
                return 0
            raise NotImplementedError("Only asyncore specific behaviour "
                                      "implemented.")
        read = recv
        write = send
        def close(self):
            if self.fd < 0:
                return
            fd = self.fd
            self.fd = -1
            os.close(fd)
        def fileno(self):
            return self.fd
    class file_dispatcher(dispatcher):
        def __init__(self, fd, map=None):
            dispatcher.__init__(self, None, map)
            self.connected = True
            try:
                fd = fd.fileno()
            except AttributeError:
                pass
            self.set_file(fd)
            # set it to non-blocking mode
            os.set_blocking(fd, False)
        def set_file(self, fd):
            self.socket = file_wrapper(fd)
            self._fileno = self.socket.fileno()
            self.add_channel()
--- a/Lib/base64.py
+++ b/Lib/base64.py
@ -0,0 +1,595 @@
 #! /usr/bin/env python3
 """Base16, Base32, Base64 (RFC 3548), Base85 and Ascii85 data encodings"""
 # Modified 04-Oct-1995 by Jack Jansen to use binascii module
 # Modified 30-Dec-2003 by Barry Warsaw to add full RFC 3548 support
 # Modified 22-May-2007 by Guido van Rossum to use bytes everywhere
 import re
 import struct
 import binascii
 __all__ = [
    # Legacy interface exports traditional RFC 2045 Base64 encodings
    'encode', 'decode', 'encodebytes', 'decodebytes',
    # Generalized interface for other encodings
    'b64encode', 'b64decode', 'b32encode', 'b32decode',
    'b16encode', 'b16decode',
    # Base85 and Ascii85 encodings
    'b85encode', 'b85decode', 'a85encode', 'a85decode',
    # Standard Base64 encoding
    'standard_b64encode', 'standard_b64decode',
    # Some common Base64 alternatives.  As referenced by RFC 3458, see thread
    # starting at:
    #
    # http://zgp.org/pipermail/p2p-hackers/2001-September/000316.html
    'urlsafe_b64encode', 'urlsafe_b64decode',
    ]
 bytes_types = (bytes, bytearray)  # Types acceptable as binary data
 def _bytes_from_decode_data(s):
    if isinstance(s, str):
        try:
            return s.encode('ascii')
        except UnicodeEncodeError:
            raise ValueError('string argument should contain only ASCII characters')
    if isinstance(s, bytes_types):
        return s
    try:
        return memoryview(s).tobytes()
    except TypeError:
        raise TypeError("argument should be a bytes-like object or ASCII "
                        "string, not %r" % s.__class__.__name__) from None
 # Base64 encoding/decoding uses binascii
 def b64encode(s, altchars=None):
    """Encode the bytes-like object s using Base64 and return a bytes object.
    Optional altchars should be a byte string of length 2 which specifies an
    alternative alphabet for the '+' and '/' characters.  This allows an
    application to e.g. generate url or filesystem safe Base64 strings.
    """
    encoded = binascii.b2a_base64(s, newline=False)
    if altchars is not None:
        assert len(altchars) == 2, repr(altchars)
        return encoded.translate(bytes.maketrans(b'+/', altchars))
    return encoded
 def b64decode(s, altchars=None, validate=False):
    """Decode the Base64 encoded bytes-like object or ASCII string s.
    Optional altchars must be a bytes-like object or ASCII string of length 2
    which specifies the alternative alphabet used instead of the '+' and '/'
    characters.
    The result is returned as a bytes object.  A binascii.Error is raised if
    s is incorrectly padded.
    If validate is False (the default), characters that are neither in the
    normal base-64 alphabet nor the alternative alphabet are discarded prior
    to the padding check.  If validate is True, these non-alphabet characters
    in the input result in a binascii.Error.
    """
    s = _bytes_from_decode_data(s)
    if altchars is not None:
        altchars = _bytes_from_decode_data(altchars)
        assert len(altchars) == 2, repr(altchars)
        s = s.translate(bytes.maketrans(altchars, b'+/'))
    if validate and not re.match(b'^[A-Za-z0-9+/]*={0,2}$', s):
        raise binascii.Error('Non-base64 digit found')
    return binascii.a2b_base64(s)
 def standard_b64encode(s):
    """Encode bytes-like object s using the standard Base64 alphabet.
    The result is returned as a bytes object.
    """
    return b64encode(s)
 def standard_b64decode(s):
    """Decode bytes encoded with the standard Base64 alphabet.
    Argument s is a bytes-like object or ASCII string to decode.  The result
    is returned as a bytes object.  A binascii.Error is raised if the input
    is incorrectly padded.  Characters that are not in the standard alphabet
    are discarded prior to the padding check.
    """
    return b64decode(s)
 _urlsafe_encode_translation = bytes.maketrans(b'+/', b'-_')
 _urlsafe_decode_translation = bytes.maketrans(b'-_', b'+/')
 def urlsafe_b64encode(s):
    """Encode bytes using the URL- and filesystem-safe Base64 alphabet.
    Argument s is a bytes-like object to encode.  The result is returned as a
    bytes object.  The alphabet uses '-' instead of '+' and '_' instead of
    '/'.
    """
    return b64encode(s).translate(_urlsafe_encode_translation)
 def urlsafe_b64decode(s):
    """Decode bytes using the URL- and filesystem-safe Base64 alphabet.
    Argument s is a bytes-like object or ASCII string to decode.  The result
    is returned as a bytes object.  A binascii.Error is raised if the input
    is incorrectly padded.  Characters that are not in the URL-safe base-64
    alphabet, and are not a plus '+' or slash '/', are discarded prior to the
    padding check.
    The alphabet uses '-' instead of '+' and '_' instead of '/'.
    """
    s = _bytes_from_decode_data(s)
    s = s.translate(_urlsafe_decode_translation)
    return b64decode(s)
 # Base32 encoding/decoding must be done in Python
 _b32alphabet = b'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567'
 _b32tab2 = None
 _b32rev = None
 def b32encode(s):
    """Encode the bytes-like object s using Base32 and return a bytes object.
    """
    global _b32tab2
    # Delay the initialization of the table to not waste memory
    # if the function is never called
    if _b32tab2 is None:
        b32tab = [bytes((i,)) for i in _b32alphabet]
        _b32tab2 = [a + b for a in b32tab for b in b32tab]
        b32tab = None
    if not isinstance(s, bytes_types):
        s = memoryview(s).tobytes()
    leftover = len(s) % 5
    # Pad the last quantum with zero bits if necessary
    if leftover:
        s = s + b'\0' * (5 - leftover)  # Don't use += !
    encoded = bytearray()
    from_bytes = int.from_bytes
    b32tab2 = _b32tab2
    for i in range(0, len(s), 5):
        c = from_bytes(s[i: i + 5], 'big')
        encoded += (b32tab2[c >> 30] +           # bits 1 - 10
                    b32tab2[(c >> 20) & 0x3ff] + # bits 11 - 20
                    b32tab2[(c >> 10) & 0x3ff] + # bits 21 - 30
                    b32tab2[c & 0x3ff]           # bits 31 - 40
                   )
    # Adjust for any leftover partial quanta
    if leftover == 1:
        encoded[-6:] = b'======'
    elif leftover == 2:
        encoded[-4:] = b'===='
    elif leftover == 3:
        encoded[-3:] = b'==='
    elif leftover == 4:
        encoded[-1:] = b'='
    return bytes(encoded)
 def b32decode(s, casefold=False, map01=None):
    """Decode the Base32 encoded bytes-like object or ASCII string s.
    Optional casefold is a flag specifying whether a lowercase alphabet is
    acceptable as input.  For security purposes, the default is False.
    RFC 3548 allows for optional mapping of the digit 0 (zero) to the
    letter O (oh), and for optional mapping of the digit 1 (one) to
    either the letter I (eye) or letter L (el).  The optional argument
    map01 when not None, specifies which letter the digit 1 should be
    mapped to (when map01 is not None, the digit 0 is always mapped to
    the letter O).  For security purposes the default is None, so that
    0 and 1 are not allowed in the input.
    The result is returned as a bytes object.  A binascii.Error is raised if
    the input is incorrectly padded or if there are non-alphabet
    characters present in the input.
    """
    global _b32rev
    # Delay the initialization of the table to not waste memory
    # if the function is never called
    if _b32rev is None:
        _b32rev = {v: k for k, v in enumerate(_b32alphabet)}
    s = _bytes_from_decode_data(s)
    if len(s) % 8:
        raise binascii.Error('Incorrect padding')
    # Handle section 2.4 zero and one mapping.  The flag map01 will be either
    # False, or the character to map the digit 1 (one) to.  It should be
    # either L (el) or I (eye).
    if map01 is not None:
        map01 = _bytes_from_decode_data(map01)
        assert len(map01) == 1, repr(map01)
        s = s.translate(bytes.maketrans(b'01', b'O' + map01))
    if casefold:
        s = s.upper()
    # Strip off pad characters from the right.  We need to count the pad
    # characters because this will tell us how many null bytes to remove from
    # the end of the decoded string.
    l = len(s)
    s = s.rstrip(b'=')
    padchars = l - len(s)
    # Now decode the full quanta
    decoded = bytearray()
    b32rev = _b32rev
    for i in range(0, len(s), 8):
        quanta = s[i: i + 8]
        acc = 0
        try:
            for c in quanta:
                acc = (acc << 5) + b32rev[c]
        except KeyError:
            raise binascii.Error('Non-base32 digit found') from None
        decoded += acc.to_bytes(5, 'big')
    # Process the last, partial quanta
    if l % 8 or padchars not in {0, 1, 3, 4, 6}:
        raise binascii.Error('Incorrect padding')
    if padchars and decoded:
        acc <<= 5 * padchars
        last = acc.to_bytes(5, 'big')
        leftover = (43 - 5 * padchars) // 8  # 1: 4, 3: 3, 4: 2, 6: 1
        decoded[-5:] = last[:leftover]
    return bytes(decoded)
 # RFC 3548, Base 16 Alphabet specifies uppercase, but hexlify() returns
 # lowercase.  The RFC also recommends against accepting input case
 # insensitively.
 def b16encode(s):
    """Encode the bytes-like object s using Base16 and return a bytes object.
    """
    return binascii.hexlify(s).upper()
 def b16decode(s, casefold=False):
    """Decode the Base16 encoded bytes-like object or ASCII string s.
    Optional casefold is a flag specifying whether a lowercase alphabet is
    acceptable as input.  For security purposes, the default is False.
    The result is returned as a bytes object.  A binascii.Error is raised if
    s is incorrectly padded or if there are non-alphabet characters present
    in the input.
    """
    s = _bytes_from_decode_data(s)
    if casefold:
        s = s.upper()
    if re.search(b'[^0-9A-F]', s):
        raise binascii.Error('Non-base16 digit found')
    return binascii.unhexlify(s)
 #
 # Ascii85 encoding/decoding
 #
 _a85chars = None
 _a85chars2 = None
 _A85START = b"<~"
 _A85END = b"~>"
 def _85encode(b, chars, chars2, pad=False, foldnuls=False, foldspaces=False):
    # Helper function for a85encode and b85encode
    if not isinstance(b, bytes_types):
        b = memoryview(b).tobytes()
    padding = (-len(b)) % 4
    if padding:
        b = b + b'\0' * padding
    words = struct.Struct('!%dI' % (len(b) // 4)).unpack(b)
    chunks = [b'z' if foldnuls and not word else
              b'y' if foldspaces and word == 0x20202020 else
              (chars2[word // 614125] +
               chars2[word // 85 % 7225] +
               chars[word % 85])
              for word in words]
    if padding and not pad:
        if chunks[-1] == b'z':
            chunks[-1] = chars[0] * 5
        chunks[-1] = chunks[-1][:-padding]
    return b''.join(chunks)
 def a85encode(b, *, foldspaces=False, wrapcol=0, pad=False, adobe=False):
    """Encode bytes-like object b using Ascii85 and return a bytes object.
    foldspaces is an optional flag that uses the special short sequence 'y'
    instead of 4 consecutive spaces (ASCII 0x20) as supported by 'btoa'. This
    feature is not supported by the "standard" Adobe encoding.
    wrapcol controls whether the output should have newline (b'\\n') characters
    added to it. If this is non-zero, each output line will be at most this
    many characters long.
    pad controls whether the input is padded to a multiple of 4 before
    encoding. Note that the btoa implementation always pads.
    adobe controls whether the encoded byte sequence is framed with <~ and ~>,
    which is used by the Adobe implementation.
    """
    global _a85chars, _a85chars2
    # Delay the initialization of tables to not waste memory
    # if the function is never called
    if _a85chars is None:
        _a85chars = [bytes((i,)) for i in range(33, 118)]
        _a85chars2 = [(a + b) for a in _a85chars for b in _a85chars]
    result = _85encode(b, _a85chars, _a85chars2, pad, True, foldspaces)
    if adobe:
        result = _A85START + result
    if wrapcol:
        wrapcol = max(2 if adobe else 1, wrapcol)
        chunks = [result[i: i + wrapcol]
                  for i in range(0, len(result), wrapcol)]
        if adobe:
            if len(chunks[-1]) + 2 > wrapcol:
                chunks.append(b'')
        result = b'\n'.join(chunks)
    if adobe:
        result += _A85END
    return result
 def a85decode(b, *, foldspaces=False, adobe=False, ignorechars=b' \t\n\r\v'):
    """Decode the Ascii85 encoded bytes-like object or ASCII string b.
    foldspaces is a flag that specifies whether the 'y' short sequence should be
    accepted as shorthand for 4 consecutive spaces (ASCII 0x20). This feature is
    not supported by the "standard" Adobe encoding.
    adobe controls whether the input sequence is in Adobe Ascii85 format (i.e.
    is framed with <~ and ~>).
    ignorechars should be a byte string containing characters to ignore from the
    input. This should only contain whitespace characters, and by default
    contains all whitespace characters in ASCII.
    The result is returned as a bytes object.
    """
    b = _bytes_from_decode_data(b)
    if adobe:
        if not b.endswith(_A85END):
            raise ValueError(
                "Ascii85 encoded byte sequences must end "
                "with {!r}".format(_A85END)
                )
        if b.startswith(_A85START):
            b = b[2:-2]  # Strip off start/end markers
        else:
            b = b[:-2]
    #
    # We have to go through this stepwise, so as to ignore spaces and handle
    # special short sequences
    #
    packI = struct.Struct('!I').pack
    decoded = []
    decoded_append = decoded.append
    curr = []
    curr_append = curr.append
    curr_clear = curr.clear
    for x in b + b'u' * 4:
        if b'!'[0] <= x <= b'u'[0]:
            curr_append(x)
            if len(curr) == 5:
                acc = 0
                for x in curr:
                    acc = 85 * acc + (x - 33)
                try:
                    decoded_append(packI(acc))
                except struct.error:
                    raise ValueError('Ascii85 overflow') from None
                curr_clear()
        elif x == b'z'[0]:
            if curr:
                raise ValueError('z inside Ascii85 5-tuple')
            decoded_append(b'\0\0\0\0')
        elif foldspaces and x == b'y'[0]:
            if curr:
                raise ValueError('y inside Ascii85 5-tuple')
            decoded_append(b'\x20\x20\x20\x20')
        elif x in ignorechars:
            # Skip whitespace
            continue
        else:
            raise ValueError('Non-Ascii85 digit found: %c' % x)
    result = b''.join(decoded)
    padding = 4 - len(curr)
    if padding:
        # Throw away the extra padding
        result = result[:-padding]
    return result
 # The following code is originally taken (with permission) from Mercurial
 _b85alphabet = (b"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                b"abcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~")
 _b85chars = None
 _b85chars2 = None
 _b85dec = None
 def b85encode(b, pad=False):
    """Encode bytes-like object b in base85 format and return a bytes object.
    If pad is true, the input is padded with b'\\0' so its length is a multiple of
    4 bytes before encoding.
    """
    global _b85chars, _b85chars2
    # Delay the initialization of tables to not waste memory
    # if the function is never called
    if _b85chars is None:
        _b85chars = [bytes((i,)) for i in _b85alphabet]
        _b85chars2 = [(a + b) for a in _b85chars for b in _b85chars]
    return _85encode(b, _b85chars, _b85chars2, pad)
 def b85decode(b):
    """Decode the base85-encoded bytes-like object or ASCII string b
    The result is returned as a bytes object.
    """
    global _b85dec
    # Delay the initialization of tables to not waste memory
    # if the function is never called
    if _b85dec is None:
        _b85dec = [None] * 256
        for i, c in enumerate(_b85alphabet):
            _b85dec[c] = i
    b = _bytes_from_decode_data(b)
    padding = (-len(b)) % 5
    b = b + b'~' * padding
    out = []
    packI = struct.Struct('!I').pack
    for i in range(0, len(b), 5):
        chunk = b[i:i + 5]
        acc = 0
        try:
            for c in chunk:
                acc = acc * 85 + _b85dec[c]
        except TypeError:
            for j, c in enumerate(chunk):
                if _b85dec[c] is None:
                    raise ValueError('bad base85 character at position %d'
                                    % (i + j)) from None
            raise
        try:
            out.append(packI(acc))
        except struct.error:
            raise ValueError('base85 overflow in hunk starting at byte %d'
                             % i) from None
    result = b''.join(out)
    if padding:
        result = result[:-padding]
    return result
 # Legacy interface.  This code could be cleaned up since I don't believe
 # binascii has any line length limitations.  It just doesn't seem worth it
 # though.  The files should be opened in binary mode.
 MAXLINESIZE = 76 # Excluding the CRLF
 MAXBINSIZE = (MAXLINESIZE//4)*3
 def encode(input, output):
    """Encode a file; input and output are binary files."""
    while True:
        s = input.read(MAXBINSIZE)
        if not s:
            break
        while len(s) < MAXBINSIZE:
            ns = input.read(MAXBINSIZE-len(s))
            if not ns:
                break
            s += ns
        line = binascii.b2a_base64(s)
        output.write(line)
 def decode(input, output):
    """Decode a file; input and output are binary files."""
    while True:
        line = input.readline()
        if not line:
            break
        s = binascii.a2b_base64(line)
        output.write(s)
 def _input_type_check(s):
    try:
        m = memoryview(s)
    except TypeError as err:
        msg = "expected bytes-like object, not %s" % s.__class__.__name__
        raise TypeError(msg) from err
    if m.format not in ('c', 'b', 'B'):
        msg = ("expected single byte elements, not %r from %s" %
                                          (m.format, s.__class__.__name__))
        raise TypeError(msg)
    if m.ndim != 1:
        msg = ("expected 1-D data, not %d-D data from %s" %
                                          (m.ndim, s.__class__.__name__))
        raise TypeError(msg)
 def encodebytes(s):
    """Encode a bytestring into a bytes object containing multiple lines
    of base-64 data."""
    _input_type_check(s)
    pieces = []
    for i in range(0, len(s), MAXBINSIZE):
        chunk = s[i : i + MAXBINSIZE]
        pieces.append(binascii.b2a_base64(chunk))
    return b"".join(pieces)
 def encodestring(s):
    """Legacy alias of encodebytes()."""
    import warnings
    warnings.warn("encodestring() is a deprecated alias since 3.1, "
                  "use encodebytes()",
                  DeprecationWarning, 2)
    return encodebytes(s)
 def decodebytes(s):
    """Decode a bytestring of base-64 data into a bytes object."""
    _input_type_check(s)
    return binascii.a2b_base64(s)
 def decodestring(s):
    """Legacy alias of decodebytes()."""
    import warnings
    warnings.warn("decodestring() is a deprecated alias since Python 3.1, "
                  "use decodebytes()",
                  DeprecationWarning, 2)
    return decodebytes(s)
 # Usable as a script...
 def main():
    """Small main program"""
    import sys, getopt
    try:
        opts, args = getopt.getopt(sys.argv[1:], 'deut')
    except getopt.error as msg:
        sys.stdout = sys.stderr
        print(msg)
        print("""usage: %s [-d|-e|-u|-t] [file|-]
        -d, -u: decode
        -e: encode (default)
        -t: encode and decode string 'Aladdin:open sesame'"""%sys.argv[0])
        sys.exit(2)
    func = encode
    for o, a in opts:
        if o == '-e': func = encode
        if o == '-d': func = decode
        if o == '-u': func = decode
        if o == '-t': test(); return
    if args and args[0] != '-':
        with open(args[0], 'rb') as f:
            func(f, sys.stdout.buffer)
    else:
        func(sys.stdin.buffer, sys.stdout.buffer)
 def test():
    s0 = b"Aladdin:open sesame"
    print(repr(s0))
    s1 = encodebytes(s0)
    print(repr(s1))
    s2 = decodebytes(s1)
    print(repr(s2))
    assert s0 == s2
 if __name__ == '__main__':
    main()
--- a/Lib/bdb.py
+++ b/Lib/bdb.py
@ -0,0 +1,869 @@
 """Debugger basics"""
 import fnmatch
 import sys
 import os
 from inspect import CO_GENERATOR, CO_COROUTINE, CO_ASYNC_GENERATOR
 __all__ = ["BdbQuit", "Bdb", "Breakpoint"]
 GENERATOR_AND_COROUTINE_FLAGS = CO_GENERATOR | CO_COROUTINE | CO_ASYNC_GENERATOR
 class BdbQuit(Exception):
    """Exception to give up completely."""
 class Bdb:
    """Generic Python debugger base class.
    This class takes care of details of the trace facility;
    a derived class should implement user interaction.
    The standard debugger class (pdb.Pdb) is an example.
    The optional skip argument must be an iterable of glob-style
    module name patterns.  The debugger will not step into frames
    that originate in a module that matches one of these patterns.
    Whether a frame is considered to originate in a certain module
    is determined by the __name__ in the frame globals.
    """
    def __init__(self, skip=None):
        self.skip = set(skip) if skip else None
        self.breaks = {}
        self.fncache = {}
        self.frame_returning = None
    def canonic(self, filename):
        """Return canonical form of filename.
        For real filenames, the canonical form is a case-normalized (on
        case insenstive filesystems) absolute path.  'Filenames' with
        angle brackets, such as "<stdin>", generated in interactive
        mode, are returned unchanged.
        """
        if filename == "<" + filename[1:-1] + ">":
            return filename
        canonic = self.fncache.get(filename)
        if not canonic:
            canonic = os.path.abspath(filename)
            canonic = os.path.normcase(canonic)
            self.fncache[filename] = canonic
        return canonic
    def reset(self):
        """Set values of attributes as ready to start debugging."""
        import linecache
        linecache.checkcache()
        self.botframe = None
        self._set_stopinfo(None, None)
    def trace_dispatch(self, frame, event, arg):
        """Dispatch a trace function for debugged frames based on the event.
        This function is installed as the trace function for debugged
        frames. Its return value is the new trace function, which is
        usually itself. The default implementation decides how to
        dispatch a frame, depending on the type of event (passed in as a
        string) that is about to be executed.
        The event can be one of the following:
            line: A new line of code is going to be executed.
            call: A function is about to be called or another code block
                  is entered.
            return: A function or other code block is about to return.
            exception: An exception has occurred.
            c_call: A C function is about to be called.
            c_return: A C function has returned.
            c_exception: A C function has raised an exception.
        For the Python events, specialized functions (see the dispatch_*()
        methods) are called.  For the C events, no action is taken.
        The arg parameter depends on the previous event.
        """
        if self.quitting:
            return # None
        if event == 'line':
            return self.dispatch_line(frame)
        if event == 'call':
            return self.dispatch_call(frame, arg)
        if event == 'return':
            return self.dispatch_return(frame, arg)
        if event == 'exception':
            return self.dispatch_exception(frame, arg)
        if event == 'c_call':
            return self.trace_dispatch
        if event == 'c_exception':
            return self.trace_dispatch
        if event == 'c_return':
            return self.trace_dispatch
        print('bdb.Bdb.dispatch: unknown debugging event:', repr(event))
        return self.trace_dispatch
    def dispatch_line(self, frame):
        """Invoke user function and return trace function for line event.
        If the debugger stops on the current line, invoke
        self.user_line(). Raise BdbQuit if self.quitting is set.
        Return self.trace_dispatch to continue tracing in this scope.
        """
        if self.stop_here(frame) or self.break_here(frame):
            self.user_line(frame)
            if self.quitting: raise BdbQuit
        return self.trace_dispatch
    def dispatch_call(self, frame, arg):
        """Invoke user function and return trace function for call event.
        If the debugger stops on this function call, invoke
        self.user_call(). Raise BbdQuit if self.quitting is set.
        Return self.trace_dispatch to continue tracing in this scope.
        """
        # XXX 'arg' is no longer used
        if self.botframe is None:
            # First call of dispatch since reset()
            self.botframe = frame.f_back # (CT) Note that this may also be None!
            return self.trace_dispatch
        if not (self.stop_here(frame) or self.break_anywhere(frame)):
            # No need to trace this function
            return # None
        # Ignore call events in generator except when stepping.
        if self.stopframe and frame.f_code.co_flags & GENERATOR_AND_COROUTINE_FLAGS:
            return self.trace_dispatch
        self.user_call(frame, arg)
        if self.quitting: raise BdbQuit
        return self.trace_dispatch
    def dispatch_return(self, frame, arg):
        """Invoke user function and return trace function for return event.
        If the debugger stops on this function return, invoke
        self.user_return(). Raise BdbQuit if self.quitting is set.
        Return self.trace_dispatch to continue tracing in this scope.
        """
        if self.stop_here(frame) or frame == self.returnframe:
            # Ignore return events in generator except when stepping.
            if self.stopframe and frame.f_code.co_flags & GENERATOR_AND_COROUTINE_FLAGS:
                return self.trace_dispatch
            try:
                self.frame_returning = frame
                self.user_return(frame, arg)
            finally:
                self.frame_returning = None
            if self.quitting: raise BdbQuit
            # The user issued a 'next' or 'until' command.
            if self.stopframe is frame and self.stoplineno != -1:
                self._set_stopinfo(None, None)
        return self.trace_dispatch
    def dispatch_exception(self, frame, arg):
        """Invoke user function and return trace function for exception event.
        If the debugger stops on this exception, invoke
        self.user_exception(). Raise BdbQuit if self.quitting is set.
        Return self.trace_dispatch to continue tracing in this scope.
        """
        if self.stop_here(frame):
            # When stepping with next/until/return in a generator frame, skip
            # the internal StopIteration exception (with no traceback)
            # triggered by a subiterator run with the 'yield from' statement.
            if not (frame.f_code.co_flags & GENERATOR_AND_COROUTINE_FLAGS
                    and arg[0] is StopIteration and arg[2] is None):
                self.user_exception(frame, arg)
                if self.quitting: raise BdbQuit
        # Stop at the StopIteration or GeneratorExit exception when the user
        # has set stopframe in a generator by issuing a return command, or a
        # next/until command at the last statement in the generator before the
        # exception.
        elif (self.stopframe and frame is not self.stopframe
                and self.stopframe.f_code.co_flags & GENERATOR_AND_COROUTINE_FLAGS
                and arg[0] in (StopIteration, GeneratorExit)):
            self.user_exception(frame, arg)
            if self.quitting: raise BdbQuit
        return self.trace_dispatch
    # Normally derived classes don't override the following
    # methods, but they may if they want to redefine the
    # definition of stopping and breakpoints.
    def is_skipped_module(self, module_name):
        "Return True if module_name matches any skip pattern."
        for pattern in self.skip:
            if fnmatch.fnmatch(module_name, pattern):
                return True
        return False
    def stop_here(self, frame):
        "Return True if frame is below the starting frame in the stack."
        # (CT) stopframe may now also be None, see dispatch_call.
        # (CT) the former test for None is therefore removed from here.
        if self.skip and \
               self.is_skipped_module(frame.f_globals.get('__name__')):
            return False
        if frame is self.stopframe:
            if self.stoplineno == -1:
                return False
            return frame.f_lineno >= self.stoplineno
        if not self.stopframe:
            return True
        return False
    def break_here(self, frame):
        """Return True if there is an effective breakpoint for this line.
        Check for line or function breakpoint and if in effect.
        Delete temporary breakpoints if effective() says to.
        """
        filename = self.canonic(frame.f_code.co_filename)
        if filename not in self.breaks:
            return False
        lineno = frame.f_lineno
        if lineno not in self.breaks[filename]:
            # The line itself has no breakpoint, but maybe the line is the
            # first line of a function with breakpoint set by function name.
            lineno = frame.f_code.co_firstlineno
            if lineno not in self.breaks[filename]:
                return False
        # flag says ok to delete temp. bp
        (bp, flag) = effective(filename, lineno, frame)
        if bp:
            self.currentbp = bp.number
            if (flag and bp.temporary):
                self.do_clear(str(bp.number))
            return True
        else:
            return False
    def do_clear(self, arg):
        """Remove temporary breakpoint.
        Must implement in derived classes or get NotImplementedError.
        """
        raise NotImplementedError("subclass of bdb must implement do_clear()")
    def break_anywhere(self, frame):
        """Return True if there is any breakpoint for frame's filename.
        """
        return self.canonic(frame.f_code.co_filename) in self.breaks
    # Derived classes should override the user_* methods
    # to gain control.
    def user_call(self, frame, argument_list):
        """Called if we might stop in a function."""
        pass
    def user_line(self, frame):
        """Called when we stop or break at a line."""
        pass
    def user_return(self, frame, return_value):
        """Called when a return trap is set here."""
        pass
    def user_exception(self, frame, exc_info):
        """Called when we stop on an exception."""
        pass
    def _set_stopinfo(self, stopframe, returnframe, stoplineno=0):
        """Set the attributes for stopping.
        If stoplineno is greater than or equal to 0, then stop at line
        greater than or equal to the stopline.  If stoplineno is -1, then
        don't stop at all.
        """
        self.stopframe = stopframe
        self.returnframe = returnframe
        self.quitting = False
        # stoplineno >= 0 means: stop at line >= the stoplineno
        # stoplineno -1 means: don't stop at all
        self.stoplineno = stoplineno
    # Derived classes and clients can call the following methods
    # to affect the stepping state.
    def set_until(self, frame, lineno=None):
        """Stop when the line with the lineno greater than the current one is
        reached or when returning from current frame."""
        # the name "until" is borrowed from gdb
        if lineno is None:
            lineno = frame.f_lineno + 1
        self._set_stopinfo(frame, frame, lineno)
    def set_step(self):
        """Stop after one line of code."""
        # Issue #13183: pdb skips frames after hitting a breakpoint and running
        # step commands.
        # Restore the trace function in the caller (that may not have been set
        # for performance reasons) when returning from the current frame.
        if self.frame_returning:
            caller_frame = self.frame_returning.f_back
            if caller_frame and not caller_frame.f_trace:
                caller_frame.f_trace = self.trace_dispatch
        self._set_stopinfo(None, None)
    def set_next(self, frame):
        """Stop on the next line in or below the given frame."""
        self._set_stopinfo(frame, None)
    def set_return(self, frame):
        """Stop when returning from the given frame."""
        if frame.f_code.co_flags & GENERATOR_AND_COROUTINE_FLAGS:
            self._set_stopinfo(frame, None, -1)
        else:
            self._set_stopinfo(frame.f_back, frame)
    def set_trace(self, frame=None):
        """Start debugging from frame.
        If frame is not specified, debugging starts from caller's frame.
        """
        if frame is None:
            frame = sys._getframe().f_back
        self.reset()
        while frame:
            frame.f_trace = self.trace_dispatch
            self.botframe = frame
            frame = frame.f_back
        self.set_step()
        sys.settrace(self.trace_dispatch)
    def set_continue(self):
        """Stop only at breakpoints or when finished.
        If there are no breakpoints, set the system trace function to None.
        """
        # Don't stop except at breakpoints or when finished
        self._set_stopinfo(self.botframe, None, -1)
        if not self.breaks:
            # no breakpoints; run without debugger overhead
            sys.settrace(None)
            frame = sys._getframe().f_back
            while frame and frame is not self.botframe:
                del frame.f_trace
                frame = frame.f_back
    def set_quit(self):
        """Set quitting attribute to True.
        Raises BdbQuit exception in the next call to a dispatch_*() method.
        """
        self.stopframe = self.botframe
        self.returnframe = None
        self.quitting = True
        sys.settrace(None)
    # Derived classes and clients can call the following methods
    # to manipulate breakpoints.  These methods return an
    # error message if something went wrong, None if all is well.
    # Set_break prints out the breakpoint line and file:lineno.
    # Call self.get_*break*() to see the breakpoints or better
    # for bp in Breakpoint.bpbynumber: if bp: bp.bpprint().
    def set_break(self, filename, lineno, temporary=False, cond=None,
                  funcname=None):
        """Set a new breakpoint for filename:lineno.
        If lineno doesn't exist for the filename, return an error message.
        The filename should be in canonical form.
        """
        filename = self.canonic(filename)
        import linecache # Import as late as possible
        line = linecache.getline(filename, lineno)
        if not line:
            return 'Line %s:%d does not exist' % (filename, lineno)
        list = self.breaks.setdefault(filename, [])
        if lineno not in list:
            list.append(lineno)
        bp = Breakpoint(filename, lineno, temporary, cond, funcname)
        return None
    def _prune_breaks(self, filename, lineno):
        """Prune breakpoints for filname:lineno.
        A list of breakpoints is maintained in the Bdb instance and in
        the Breakpoint class.  If a breakpoint in the Bdb instance no
        longer exists in the Breakpoint class, then it's removed from the
        Bdb instance.
        """
        if (filename, lineno) not in Breakpoint.bplist:
            self.breaks[filename].remove(lineno)
        if not self.breaks[filename]:
            del self.breaks[filename]
    def clear_break(self, filename, lineno):
        """Delete breakpoints for filename:lineno.
        If no breakpoints were set, return an error message.
        """
        filename = self.canonic(filename)
        if filename not in self.breaks:
            return 'There are no breakpoints in %s' % filename
        if lineno not in self.breaks[filename]:
            return 'There is no breakpoint at %s:%d' % (filename, lineno)
        # If there's only one bp in the list for that file,line
        # pair, then remove the breaks entry
        for bp in Breakpoint.bplist[filename, lineno][:]:
            bp.deleteMe()
        self._prune_breaks(filename, lineno)
        return None
    def clear_bpbynumber(self, arg):
        """Delete a breakpoint by its index in Breakpoint.bpbynumber.
        If arg is invalid, return an error message.
        """
        try:
            bp = self.get_bpbynumber(arg)
        except ValueError as err:
            return str(err)
        bp.deleteMe()
        self._prune_breaks(bp.file, bp.line)
        return None
    def clear_all_file_breaks(self, filename):
        """Delete all breakpoints in filename.
        If none were set, return an error message.
        """
        filename = self.canonic(filename)
        if filename not in self.breaks:
            return 'There are no breakpoints in %s' % filename
        for line in self.breaks[filename]:
            blist = Breakpoint.bplist[filename, line]
            for bp in blist:
                bp.deleteMe()
        del self.breaks[filename]
        return None
    def clear_all_breaks(self):
        """Delete all existing breakpoints.
        If none were set, return an error message.
        """
        if not self.breaks:
            return 'There are no breakpoints'
        for bp in Breakpoint.bpbynumber:
            if bp:
                bp.deleteMe()
        self.breaks = {}
        return None
    def get_bpbynumber(self, arg):
        """Return a breakpoint by its index in Breakpoint.bybpnumber.
        For invalid arg values or if the breakpoint doesn't exist,
        raise a ValueError.
        """
        if not arg:
            raise ValueError('Breakpoint number expected')
        try:
            number = int(arg)
        except ValueError:
            raise ValueError('Non-numeric breakpoint number %s' % arg) from None
        try:
            bp = Breakpoint.bpbynumber[number]
        except IndexError:
            raise ValueError('Breakpoint number %d out of range' % number) from None
        if bp is None:
            raise ValueError('Breakpoint %d already deleted' % number)
        return bp
    def get_break(self, filename, lineno):
        """Return True if there is a breakpoint for filename:lineno."""
        filename = self.canonic(filename)
        return filename in self.breaks and \
            lineno in self.breaks[filename]
    def get_breaks(self, filename, lineno):
        """Return all breakpoints for filename:lineno.
        If no breakpoints are set, return an empty list.
        """
        filename = self.canonic(filename)
        return filename in self.breaks and \
            lineno in self.breaks[filename] and \
            Breakpoint.bplist[filename, lineno] or []
    def get_file_breaks(self, filename):
        """Return all lines with breakpoints for filename.
        If no breakpoints are set, return an empty list.
        """
        filename = self.canonic(filename)
        if filename in self.breaks:
            return self.breaks[filename]
        else:
            return []
    def get_all_breaks(self):
        """Return all breakpoints that are set."""
        return self.breaks
    # Derived classes and clients can call the following method
    # to get a data structure representing a stack trace.
    def get_stack(self, f, t):
        """Return a list of (frame, lineno) in a stack trace and a size.
        List starts with original calling frame, if there is one.
        Size may be number of frames above or below f.
        """
        stack = []
        if t and t.tb_frame is f:
            t = t.tb_next
        while f is not None:
            stack.append((f, f.f_lineno))
            if f is self.botframe:
                break
            f = f.f_back
        stack.reverse()
        i = max(0, len(stack) - 1)
        while t is not None:
            stack.append((t.tb_frame, t.tb_lineno))
            t = t.tb_next
        if f is None:
            i = max(0, len(stack) - 1)
        return stack, i
    def format_stack_entry(self, frame_lineno, lprefix=': '):
        """Return a string with information about a stack entry.
        The stack entry frame_lineno is a (frame, lineno) tuple.  The
        return string contains the canonical filename, the function name
        or '<lambda>', the input arguments, the return value, and the
        line of code (if it exists).
        """
        import linecache, reprlib
        frame, lineno = frame_lineno
        filename = self.canonic(frame.f_code.co_filename)
        s = '%s(%r)' % (filename, lineno)
        if frame.f_code.co_name:
            s += frame.f_code.co_name
        else:
            s += "<lambda>"
        if '__args__' in frame.f_locals:
            args = frame.f_locals['__args__']
        else:
            args = None
        if args:
            s += reprlib.repr(args)
        else:
            s += '()'
        if '__return__' in frame.f_locals:
            rv = frame.f_locals['__return__']
            s += '->'
            s += reprlib.repr(rv)
        line = linecache.getline(filename, lineno, frame.f_globals)
        if line:
            s += lprefix + line.strip()
        return s
    # The following methods can be called by clients to use
    # a debugger to debug a statement or an expression.
    # Both can be given as a string, or a code object.
    def run(self, cmd, globals=None, locals=None):
        """Debug a statement executed via the exec() function.
        globals defaults to __main__.dict; locals defaults to globals.
        """
        if globals is None:
            import __main__
            globals = __main__.__dict__
        if locals is None:
            locals = globals
        self.reset()
        if isinstance(cmd, str):
            cmd = compile(cmd, "<string>", "exec")
        sys.settrace(self.trace_dispatch)
        try:
            exec(cmd, globals, locals)
        except BdbQuit:
            pass
        finally:
            self.quitting = True
            sys.settrace(None)
    def runeval(self, expr, globals=None, locals=None):
        """Debug an expression executed via the eval() function.
        globals defaults to __main__.dict; locals defaults to globals.
        """
        if globals is None:
            import __main__
            globals = __main__.__dict__
        if locals is None:
            locals = globals
        self.reset()
        sys.settrace(self.trace_dispatch)
        try:
            return eval(expr, globals, locals)
        except BdbQuit:
            pass
        finally:
            self.quitting = True
            sys.settrace(None)
    def runctx(self, cmd, globals, locals):
        """For backwards-compatibility.  Defers to run()."""
        # B/W compatibility
        self.run(cmd, globals, locals)
    # This method is more useful to debug a single function call.
    def runcall(self, func, *args, **kwds):
        """Debug a single function call.
        Return the result of the function call.
        """
        self.reset()
        sys.settrace(self.trace_dispatch)
        res = None
        try:
            res = func(*args, **kwds)
        except BdbQuit:
            pass
        finally:
            self.quitting = True
            sys.settrace(None)
        return res
 def set_trace():
    """Start debugging with a Bdb instance from the caller's frame."""
    Bdb().set_trace()
 class Breakpoint:
    """Breakpoint class.
    Implements temporary breakpoints, ignore counts, disabling and
    (re)-enabling, and conditionals.
    Breakpoints are indexed by number through bpbynumber and by
    the (file, line) tuple using bplist.  The former points to a
    single instance of class Breakpoint.  The latter points to a
    list of such instances since there may be more than one
    breakpoint per line.
    When creating a breakpoint, its associated filename should be
    in canonical form.  If funcname is defined, a breakpoint hit will be
    counted when the first line of that function is executed.  A
    conditional breakpoint always counts a hit.
    """
    # XXX Keeping state in the class is a mistake -- this means
    # you cannot have more than one active Bdb instance.
    next = 1        # Next bp to be assigned
    bplist = {}     # indexed by (file, lineno) tuple
    bpbynumber = [None] # Each entry is None or an instance of Bpt
                # index 0 is unused, except for marking an
                # effective break .... see effective()
    def __init__(self, file, line, temporary=False, cond=None, funcname=None):
        self.funcname = funcname
        # Needed if funcname is not None.
        self.func_first_executable_line = None
        self.file = file    # This better be in canonical form!
        self.line = line
        self.temporary = temporary
        self.cond = cond
        self.enabled = True
        self.ignore = 0
        self.hits = 0
        self.number = Breakpoint.next
        Breakpoint.next += 1
        # Build the two lists
        self.bpbynumber.append(self)
        if (file, line) in self.bplist:
            self.bplist[file, line].append(self)
        else:
            self.bplist[file, line] = [self]
    def deleteMe(self):
        """Delete the breakpoint from the list associated to a file:line.
        If it is the last breakpoint in that position, it also deletes
        the entry for the file:line.
        """
        index = (self.file, self.line)
        self.bpbynumber[self.number] = None   # No longer in list
        self.bplist[index].remove(self)
        if not self.bplist[index]:
            # No more bp for this f:l combo
            del self.bplist[index]
    def enable(self):
        """Mark the breakpoint as enabled."""
        self.enabled = True
    def disable(self):
        """Mark the breakpoint as disabled."""
        self.enabled = False
    def bpprint(self, out=None):
        """Print the output of bpformat().
        The optional out argument directs where the output is sent
        and defaults to standard output.
        """
        if out is None:
            out = sys.stdout
        print(self.bpformat(), file=out)
    def bpformat(self):
        """Return a string with information about the breakpoint.
        The information includes the breakpoint number, temporary
        status, file:line position, break condition, number of times to
        ignore, and number of times hit.
        """
        if self.temporary:
            disp = 'del  '
        else:
            disp = 'keep '
        if self.enabled:
            disp = disp + 'yes  '
        else:
            disp = disp + 'no   '
        ret = '%-4dbreakpoint   %s at %s:%d' % (self.number, disp,
                                                self.file, self.line)
        if self.cond:
            ret += '\n\tstop only if %s' % (self.cond,)
        if self.ignore:
            ret += '\n\tignore next %d hits' % (self.ignore,)
        if self.hits:
            if self.hits > 1:
                ss = 's'
            else:
                ss = ''
            ret += '\n\tbreakpoint already hit %d time%s' % (self.hits, ss)
        return ret
    def __str__(self):
        "Return a condensed description of the breakpoint."
        return 'breakpoint %s at %s:%s' % (self.number, self.file, self.line)
 # -----------end of Breakpoint class----------
 def checkfuncname(b, frame):
    """Return True if break should happen here.
    Whether a break should happen depends on the way that b (the breakpoint)
    was set.  If it was set via line number, check if b.line is the same as
    the one in the frame.  If it was set via function name, check if this is
    the right function and if it is on the first executable line.
    """
    if not b.funcname:
        # Breakpoint was set via line number.
        if b.line != frame.f_lineno:
            # Breakpoint was set at a line with a def statement and the function
            # defined is called: don't break.
            return False
        return True
    # Breakpoint set via function name.
    if frame.f_code.co_name != b.funcname:
        # It's not a function call, but rather execution of def statement.
        return False
    # We are in the right frame.
    if not b.func_first_executable_line:
        # The function is entered for the 1st time.
        b.func_first_executable_line = frame.f_lineno
    if b.func_first_executable_line != frame.f_lineno:
        # But we are not at the first line number: don't break.
        return False
    return True
 # Determines if there is an effective (active) breakpoint at this
 # line of code.  Returns breakpoint number or 0 if none
 def effective(file, line, frame):
    """Determine which breakpoint for this file:line is to be acted upon.
    Called only if we know there is a breakpoint at this location.  Return
    the breakpoint that was triggered and a boolean that indicates if it is
    ok to delete a temporary breakpoint.  Return (None, None) if there is no
    matching breakpoint.
    """
    possibles = Breakpoint.bplist[file, line]
    for b in possibles:
        if not b.enabled:
            continue
        if not checkfuncname(b, frame):
            continue
        # Count every hit when bp is enabled
        b.hits += 1
        if not b.cond:
            # If unconditional, and ignoring go on to next, else break
            if b.ignore > 0:
                b.ignore -= 1
                continue
            else:
                # breakpoint and marker that it's ok to delete if temporary
                return (b, True)
        else:
            # Conditional bp.
            # Ignore count applies only to those bpt hits where the
            # condition evaluates to true.
            try:
                val = eval(b.cond, frame.f_globals, frame.f_locals)
                if val:
                    if b.ignore > 0:
                        b.ignore -= 1
                        # continue
                    else:
                        return (b, True)
                # else:
                #   continue
            except:
                # if eval fails, most conservative thing is to stop on
                # breakpoint regardless of ignore count.  Don't delete
                # temporary, as another hint to user.
                return (b, False)
    return (None, None)
 # -------------------- testing --------------------
 class Tdb(Bdb):
    def user_call(self, frame, args):
        name = frame.f_code.co_name
        if not name: name = '???'
        print('+++ call', name, args)
    def user_line(self, frame):
        import linecache
        name = frame.f_code.co_name
        if not name: name = '???'
        fn = self.canonic(frame.f_code.co_filename)
        line = linecache.getline(fn, frame.f_lineno, frame.f_globals)
        print('+++', fn, frame.f_lineno, name, ':', line.strip())
    def user_return(self, frame, retval):
        print('+++ return', retval)
    def user_exception(self, frame, exc_stuff):
        print('+++ exception', exc_stuff)
        self.set_continue()
 def foo(n):
    print('foo(', n, ')')
    x = bar(n*10)
    print('bar returned', x)
 def bar(a):
    print('bar(', a, ')')
    return a/2
 def test():
    t = Tdb()
    t.run('import bdb; bdb.foo(10)')
--- a/Lib/binhex.py
+++ b/Lib/binhex.py
@ -0,0 +1,479 @@
 """Macintosh binhex compression/decompression.
 easy interface:
 binhex(inputfilename, outputfilename)
 hexbin(inputfilename, outputfilename)
 """
 #
 # Jack Jansen, CWI, August 1995.
 #
 # The module is supposed to be as compatible as possible. Especially the
 # easy interface should work "as expected" on any platform.
 # XXXX Note: currently, textfiles appear in mac-form on all platforms.
 # We seem to lack a simple character-translate in python.
 # (we should probably use ISO-Latin-1 on all but the mac platform).
 # XXXX The simple routines are too simple: they expect to hold the complete
 # files in-core. Should be fixed.
 # XXXX It would be nice to handle AppleDouble format on unix
 # (for servers serving macs).
 # XXXX I don't understand what happens when you get 0x90 times the same byte on
 # input. The resulting code (xx 90 90) would appear to be interpreted as an
 # escaped *value* of 0x90. All coders I've seen appear to ignore this nicety...
 #
 import io
 import os
 import struct
 import binascii
 __all__ = ["binhex","hexbin","Error"]
 class Error(Exception):
    pass
 # States (what have we written)
 _DID_HEADER = 0
 _DID_DATA = 1
 # Various constants
 REASONABLY_LARGE = 32768  # Minimal amount we pass the rle-coder
 LINELEN = 64
 RUNCHAR = b"\x90"
 #
 # This code is no longer byte-order dependent
 class FInfo:
    def __init__(self):
        self.Type = '????'
        self.Creator = '????'
        self.Flags = 0
 def getfileinfo(name):
    finfo = FInfo()
    with io.open(name, 'rb') as fp:
        # Quick check for textfile
        data = fp.read(512)
        if 0 not in data:
            finfo.Type = 'TEXT'
        fp.seek(0, 2)
        dsize = fp.tell()
    dir, file = os.path.split(name)
    file = file.replace(':', '-', 1)
    return file, finfo, dsize, 0
 class openrsrc:
    def __init__(self, *args):
        pass
    def read(self, *args):
        return b''
    def write(self, *args):
        pass
    def close(self):
        pass
 class _Hqxcoderengine:
    """Write data to the coder in 3-byte chunks"""
    def __init__(self, ofp):
        self.ofp = ofp
        self.data = b''
        self.hqxdata = b''
        self.linelen = LINELEN - 1
    def write(self, data):
        self.data = self.data + data
        datalen = len(self.data)
        todo = (datalen // 3) * 3
        data = self.data[:todo]
        self.data = self.data[todo:]
        if not data:
            return
        self.hqxdata = self.hqxdata + binascii.b2a_hqx(data)
        self._flush(0)
    def _flush(self, force):
        first = 0
        while first <= len(self.hqxdata) - self.linelen:
            last = first + self.linelen
            self.ofp.write(self.hqxdata[first:last] + b'\n')
            self.linelen = LINELEN
            first = last
        self.hqxdata = self.hqxdata[first:]
        if force:
            self.ofp.write(self.hqxdata + b':\n')
    def close(self):
        if self.data:
            self.hqxdata = self.hqxdata + binascii.b2a_hqx(self.data)
        self._flush(1)
        self.ofp.close()
        del self.ofp
 class _Rlecoderengine:
    """Write data to the RLE-coder in suitably large chunks"""
    def __init__(self, ofp):
        self.ofp = ofp
        self.data = b''
    def write(self, data):
        self.data = self.data + data
        if len(self.data) < REASONABLY_LARGE:
            return
        rledata = binascii.rlecode_hqx(self.data)
        self.ofp.write(rledata)
        self.data = b''
    def close(self):
        if self.data:
            rledata = binascii.rlecode_hqx(self.data)
            self.ofp.write(rledata)
        self.ofp.close()
        del self.ofp
 class BinHex:
    def __init__(self, name_finfo_dlen_rlen, ofp):
        name, finfo, dlen, rlen = name_finfo_dlen_rlen
        close_on_error = False
        if isinstance(ofp, str):
            ofname = ofp
            ofp = io.open(ofname, 'wb')
            close_on_error = True
        try:
            ofp.write(b'(This file must be converted with BinHex 4.0)\r\r:')
            hqxer = _Hqxcoderengine(ofp)
            self.ofp = _Rlecoderengine(hqxer)
            self.crc = 0
            if finfo is None:
                finfo = FInfo()
            self.dlen = dlen
            self.rlen = rlen
            self._writeinfo(name, finfo)
            self.state = _DID_HEADER
        except:
            if close_on_error:
                ofp.close()
            raise
    def _writeinfo(self, name, finfo):
        nl = len(name)
        if nl > 63:
            raise Error('Filename too long')
        d = bytes([nl]) + name.encode("latin-1") + b'\0'
        tp, cr = finfo.Type, finfo.Creator
        if isinstance(tp, str):
            tp = tp.encode("latin-1")
        if isinstance(cr, str):
            cr = cr.encode("latin-1")
        d2 = tp + cr
        # Force all structs to be packed with big-endian
        d3 = struct.pack('>h', finfo.Flags)
        d4 = struct.pack('>ii', self.dlen, self.rlen)
        info = d + d2 + d3 + d4
        self._write(info)
        self._writecrc()
    def _write(self, data):
        self.crc = binascii.crc_hqx(data, self.crc)
        self.ofp.write(data)
    def _writecrc(self):
        # XXXX Should this be here??
        # self.crc = binascii.crc_hqx('\0\0', self.crc)
        if self.crc < 0:
            fmt = '>h'
        else:
            fmt = '>H'
        self.ofp.write(struct.pack(fmt, self.crc))
        self.crc = 0
    def write(self, data):
        if self.state != _DID_HEADER:
            raise Error('Writing data at the wrong time')
        self.dlen = self.dlen - len(data)
        self._write(data)
    def close_data(self):
        if self.dlen != 0:
            raise Error('Incorrect data size, diff=%r' % (self.rlen,))
        self._writecrc()
        self.state = _DID_DATA
    def write_rsrc(self, data):
        if self.state < _DID_DATA:
            self.close_data()
        if self.state != _DID_DATA:
            raise Error('Writing resource data at the wrong time')
        self.rlen = self.rlen - len(data)
        self._write(data)
    def close(self):
        if self.state is None:
            return
        try:
            if self.state < _DID_DATA:
                self.close_data()
            if self.state != _DID_DATA:
                raise Error('Close at the wrong time')
            if self.rlen != 0:
                raise Error("Incorrect resource-datasize, diff=%r" % (self.rlen,))
            self._writecrc()
        finally:
            self.state = None
            ofp = self.ofp
            del self.ofp
            ofp.close()
 def binhex(inp, out):
    """binhex(infilename, outfilename): create binhex-encoded copy of a file"""
    finfo = getfileinfo(inp)
    ofp = BinHex(finfo, out)
    with io.open(inp, 'rb') as ifp:
        # XXXX Do textfile translation on non-mac systems
        while True:
            d = ifp.read(128000)
            if not d: break
            ofp.write(d)
        ofp.close_data()
    ifp = openrsrc(inp, 'rb')
    while True:
        d = ifp.read(128000)
        if not d: break
        ofp.write_rsrc(d)
    ofp.close()
    ifp.close()
 class _Hqxdecoderengine:
    """Read data via the decoder in 4-byte chunks"""
    def __init__(self, ifp):
        self.ifp = ifp
        self.eof = 0
    def read(self, totalwtd):
        """Read at least wtd bytes (or until EOF)"""
        decdata = b''
        wtd = totalwtd
        #
        # The loop here is convoluted, since we don't really now how
        # much to decode: there may be newlines in the incoming data.
        while wtd > 0:
            if self.eof: return decdata
            wtd = ((wtd + 2) // 3) * 4
            data = self.ifp.read(wtd)
            #
            # Next problem: there may not be a complete number of
            # bytes in what we pass to a2b. Solve by yet another
            # loop.
            #
            while True:
                try:
                    decdatacur, self.eof = binascii.a2b_hqx(data)
                    break
                except binascii.Incomplete:
                    pass
                newdata = self.ifp.read(1)
                if not newdata:
                    raise Error('Premature EOF on binhex file')
                data = data + newdata
            decdata = decdata + decdatacur
            wtd = totalwtd - len(decdata)
            if not decdata and not self.eof:
                raise Error('Premature EOF on binhex file')
        return decdata
    def close(self):
        self.ifp.close()
 class _Rledecoderengine:
    """Read data via the RLE-coder"""
    def __init__(self, ifp):
        self.ifp = ifp
        self.pre_buffer = b''
        self.post_buffer = b''
        self.eof = 0
    def read(self, wtd):
        if wtd > len(self.post_buffer):
            self._fill(wtd - len(self.post_buffer))
        rv = self.post_buffer[:wtd]
        self.post_buffer = self.post_buffer[wtd:]
        return rv
    def _fill(self, wtd):
        self.pre_buffer = self.pre_buffer + self.ifp.read(wtd + 4)
        if self.ifp.eof:
            self.post_buffer = self.post_buffer + \
                binascii.rledecode_hqx(self.pre_buffer)
            self.pre_buffer = b''
            return
        #
        # Obfuscated code ahead. We have to take care that we don't
        # end up with an orphaned RUNCHAR later on. So, we keep a couple
        # of bytes in the buffer, depending on what the end of
        # the buffer looks like:
        # '\220\0\220' - Keep 3 bytes: repeated \220 (escaped as \220\0)
        # '?\220' - Keep 2 bytes: repeated something-else
        # '\220\0' - Escaped \220: Keep 2 bytes.
        # '?\220?' - Complete repeat sequence: decode all
        # otherwise: keep 1 byte.
        #
        mark = len(self.pre_buffer)
        if self.pre_buffer[-3:] == RUNCHAR + b'\0' + RUNCHAR:
            mark = mark - 3
        elif self.pre_buffer[-1:] == RUNCHAR:
            mark = mark - 2
        elif self.pre_buffer[-2:] == RUNCHAR + b'\0':
            mark = mark - 2
        elif self.pre_buffer[-2:-1] == RUNCHAR:
            pass # Decode all
        else:
            mark = mark - 1
        self.post_buffer = self.post_buffer + \
            binascii.rledecode_hqx(self.pre_buffer[:mark])
        self.pre_buffer = self.pre_buffer[mark:]
    def close(self):
        self.ifp.close()
 class HexBin:
    def __init__(self, ifp):
        if isinstance(ifp, str):
            ifp = io.open(ifp, 'rb')
        #
        # Find initial colon.
        #
        while True:
            ch = ifp.read(1)
            if not ch:
                raise Error("No binhex data found")
            # Cater for \r\n terminated lines (which show up as \n\r, hence
            # all lines start with \r)
            if ch == b'\r':
                continue
            if ch == b':':
                break
        hqxifp = _Hqxdecoderengine(ifp)
        self.ifp = _Rledecoderengine(hqxifp)
        self.crc = 0
        self._readheader()
    def _read(self, len):
        data = self.ifp.read(len)
        self.crc = binascii.crc_hqx(data, self.crc)
        return data
    def _checkcrc(self):
        filecrc = struct.unpack('>h', self.ifp.read(2))[0] & 0xffff
        #self.crc = binascii.crc_hqx('\0\0', self.crc)
        # XXXX Is this needed??
        self.crc = self.crc & 0xffff
        if filecrc != self.crc:
            raise Error('CRC error, computed %x, read %x'
                        % (self.crc, filecrc))
        self.crc = 0
    def _readheader(self):
        len = self._read(1)
        fname = self._read(ord(len))
        rest = self._read(1 + 4 + 4 + 2 + 4 + 4)
        self._checkcrc()
        type = rest[1:5]
        creator = rest[5:9]
        flags = struct.unpack('>h', rest[9:11])[0]
        self.dlen = struct.unpack('>l', rest[11:15])[0]
        self.rlen = struct.unpack('>l', rest[15:19])[0]
        self.FName = fname
        self.FInfo = FInfo()
        self.FInfo.Creator = creator
        self.FInfo.Type = type
        self.FInfo.Flags = flags
        self.state = _DID_HEADER
    def read(self, *n):
        if self.state != _DID_HEADER:
            raise Error('Read data at wrong time')
        if n:
            n = n[0]
            n = min(n, self.dlen)
        else:
            n = self.dlen
        rv = b''
        while len(rv) < n:
            rv = rv + self._read(n-len(rv))
        self.dlen = self.dlen - n
        return rv
    def close_data(self):
        if self.state != _DID_HEADER:
            raise Error('close_data at wrong time')
        if self.dlen:
            dummy = self._read(self.dlen)
        self._checkcrc()
        self.state = _DID_DATA
    def read_rsrc(self, *n):
        if self.state == _DID_HEADER:
            self.close_data()
        if self.state != _DID_DATA:
            raise Error('Read resource data at wrong time')
        if n:
            n = n[0]
            n = min(n, self.rlen)
        else:
            n = self.rlen
        self.rlen = self.rlen - n
        return self._read(n)
    def close(self):
        if self.state is None:
            return
        try:
            if self.rlen:
                dummy = self.read_rsrc(self.rlen)
            self._checkcrc()
        finally:
            self.state = None
            self.ifp.close()
 def hexbin(inp, out):
    """hexbin(infilename, outfilename) - Decode binhexed file"""
    ifp = HexBin(inp)
    finfo = ifp.FInfo
    if not out:
        out = ifp.FName
    with io.open(out, 'wb') as ofp:
        # XXXX Do translation on non-mac systems
        while True:
            d = ifp.read(128000)
            if not d: break
            ofp.write(d)
    ifp.close_data()
    d = ifp.read_rsrc(128000)
    if d:
        ofp = openrsrc(out, 'wb')
        ofp.write(d)
        while True:
            d = ifp.read_rsrc(128000)
            if not d: break
            ofp.write(d)
        ofp.close()
    ifp.close()
--- a/Lib/bisect.py
+++ b/Lib/bisect.py
@ -0,0 +1,92 @@
 """Bisection algorithms."""
 def insort_right(a, x, lo=0, hi=None):
    """Insert item x in list a, and keep it sorted assuming a is sorted.
    If x is already in a, insert it to the right of the rightmost x.
    Optional args lo (default 0) and hi (default len(a)) bound the
    slice of a to be searched.
    """
    if lo < 0:
        raise ValueError('lo must be non-negative')
    if hi is None:
        hi = len(a)
    while lo < hi:
        mid = (lo+hi)//2
        if x < a[mid]: hi = mid
        else: lo = mid+1
    a.insert(lo, x)
 def bisect_right(a, x, lo=0, hi=None):
    """Return the index where to insert item x in list a, assuming a is sorted.
    The return value i is such that all e in a[:i] have e <= x, and all e in
    a[i:] have e > x.  So if x already appears in the list, a.insert(x) will
    insert just after the rightmost x already there.
    Optional args lo (default 0) and hi (default len(a)) bound the
    slice of a to be searched.
    """
    if lo < 0:
        raise ValueError('lo must be non-negative')
    if hi is None:
        hi = len(a)
    while lo < hi:
        mid = (lo+hi)//2
        if x < a[mid]: hi = mid
        else: lo = mid+1
    return lo
 def insort_left(a, x, lo=0, hi=None):
    """Insert item x in list a, and keep it sorted assuming a is sorted.
    If x is already in a, insert it to the left of the leftmost x.
    Optional args lo (default 0) and hi (default len(a)) bound the
    slice of a to be searched.
    """
    if lo < 0:
        raise ValueError('lo must be non-negative')
    if hi is None:
        hi = len(a)
    while lo < hi:
        mid = (lo+hi)//2
        if a[mid] < x: lo = mid+1
        else: hi = mid
    a.insert(lo, x)
 def bisect_left(a, x, lo=0, hi=None):
    """Return the index where to insert item x in list a, assuming a is sorted.
    The return value i is such that all e in a[:i] have e < x, and all e in
    a[i:] have e >= x.  So if x already appears in the list, a.insert(x) will
    insert just before the leftmost x already there.
    Optional args lo (default 0) and hi (default len(a)) bound the
    slice of a to be searched.
    """
    if lo < 0:
        raise ValueError('lo must be non-negative')
    if hi is None:
        hi = len(a)
    while lo < hi:
        mid = (lo+hi)//2
        if a[mid] < x: lo = mid+1
        else: hi = mid
    return lo
 # Overwrite above definitions with a fast C implementation
 try:
    from _bisect import *
 except ImportError:
    pass
 # Create aliases
 bisect = bisect_right
 insort = insort_right
--- a/Lib/bz2.py
+++ b/Lib/bz2.py
@ -0,0 +1,357 @@
 """Interface to the libbzip2 compression library.
 This module provides a file interface, classes for incremental
 (de)compression, and functions for one-shot (de)compression.
 """
 __all__ = ["BZ2File", "BZ2Compressor", "BZ2Decompressor",
           "open", "compress", "decompress"]
 __author__ = "Nadeem Vawda <nadeem.vawda@gmail.com>"
 from builtins import open as _builtin_open
 import io
 import os
 import warnings
 import _compression
 from threading import RLock
 from _bz2 import BZ2Compressor, BZ2Decompressor
 _MODE_CLOSED   = 0
 _MODE_READ     = 1
 # Value 2 no longer used
 _MODE_WRITE    = 3
 class BZ2File(_compression.BaseStream):
    """A file object providing transparent bzip2 (de)compression.
    A BZ2File can act as a wrapper for an existing file object, or refer
    directly to a named file on disk.
    Note that BZ2File provides a *binary* file interface - data read is
    returned as bytes, and data to be written should be given as bytes.
    """
    def __init__(self, filename, mode="r", buffering=None, compresslevel=9):
        """Open a bzip2-compressed file.
        If filename is a str, bytes, or PathLike object, it gives the
        name of the file to be opened. Otherwise, it should be a file
        object, which will be used to read or write the compressed data.
        mode can be 'r' for reading (default), 'w' for (over)writing,
        'x' for creating exclusively, or 'a' for appending. These can
        equivalently be given as 'rb', 'wb', 'xb', and 'ab'.
        buffering is ignored. Its use is deprecated.
        If mode is 'w', 'x' or 'a', compresslevel can be a number between 1
        and 9 specifying the level of compression: 1 produces the least
        compression, and 9 (default) produces the most compression.
        If mode is 'r', the input file may be the concatenation of
        multiple compressed streams.
        """
        # This lock must be recursive, so that BufferedIOBase's
        # writelines() does not deadlock.
        self._lock = RLock()
        self._fp = None
        self._closefp = False
        self._mode = _MODE_CLOSED
        if buffering is not None:
            warnings.warn("Use of 'buffering' argument is deprecated",
                          DeprecationWarning)
        if not (1 <= compresslevel <= 9):
            raise ValueError("compresslevel must be between 1 and 9")
        if mode in ("", "r", "rb"):
            mode = "rb"
            mode_code = _MODE_READ
        elif mode in ("w", "wb"):
            mode = "wb"
            mode_code = _MODE_WRITE
            self._compressor = BZ2Compressor(compresslevel)
        elif mode in ("x", "xb"):
            mode = "xb"
            mode_code = _MODE_WRITE
            self._compressor = BZ2Compressor(compresslevel)
        elif mode in ("a", "ab"):
            mode = "ab"
            mode_code = _MODE_WRITE
            self._compressor = BZ2Compressor(compresslevel)
        else:
            raise ValueError("Invalid mode: %r" % (mode,))
        if isinstance(filename, (str, bytes, os.PathLike)):
            self._fp = _builtin_open(filename, mode)
            self._closefp = True
            self._mode = mode_code
        elif hasattr(filename, "read") or hasattr(filename, "write"):
            self._fp = filename
            self._mode = mode_code
        else:
            raise TypeError("filename must be a str, bytes, file or PathLike object")
        if self._mode == _MODE_READ:
            raw = _compression.DecompressReader(self._fp,
                BZ2Decompressor, trailing_error=OSError)
            self._buffer = io.BufferedReader(raw)
        else:
            self._pos = 0
    def close(self):
        """Flush and close the file.
        May be called more than once without error. Once the file is
        closed, any other operation on it will raise a ValueError.
        """
        with self._lock:
            if self._mode == _MODE_CLOSED:
                return
            try:
                if self._mode == _MODE_READ:
                    self._buffer.close()
                elif self._mode == _MODE_WRITE:
                    self._fp.write(self._compressor.flush())
                    self._compressor = None
            finally:
                try:
                    if self._closefp:
                        self._fp.close()
                finally:
                    self._fp = None
                    self._closefp = False
                    self._mode = _MODE_CLOSED
                    self._buffer = None
    @property
    def closed(self):
        """True if this file is closed."""
        return self._mode == _MODE_CLOSED
    def fileno(self):
        """Return the file descriptor for the underlying file."""
        self._check_not_closed()
        return self._fp.fileno()
    def seekable(self):
        """Return whether the file supports seeking."""
        return self.readable() and self._buffer.seekable()
    def readable(self):
        """Return whether the file was opened for reading."""
        self._check_not_closed()
        return self._mode == _MODE_READ
    def writable(self):
        """Return whether the file was opened for writing."""
        self._check_not_closed()
        return self._mode == _MODE_WRITE
    def peek(self, n=0):
        """Return buffered data without advancing the file position.
        Always returns at least one byte of data, unless at EOF.
        The exact number of bytes returned is unspecified.
        """
        with self._lock:
            self._check_can_read()
            # Relies on the undocumented fact that BufferedReader.peek()
            # always returns at least one byte (except at EOF), independent
            # of the value of n
            return self._buffer.peek(n)
    def read(self, size=-1):
        """Read up to size uncompressed bytes from the file.
        If size is negative or omitted, read until EOF is reached.
        Returns b'' if the file is already at EOF.
        """
        with self._lock:
            self._check_can_read()
            return self._buffer.read(size)
    def read1(self, size=-1):
        """Read up to size uncompressed bytes, while trying to avoid
        making multiple reads from the underlying stream. Reads up to a
        buffer's worth of data if size is negative.
        Returns b'' if the file is at EOF.
        """
        with self._lock:
            self._check_can_read()
            if size < 0:
                size = io.DEFAULT_BUFFER_SIZE
            return self._buffer.read1(size)
    def readinto(self, b):
        """Read bytes into b.
        Returns the number of bytes read (0 for EOF).
        """
        with self._lock:
            self._check_can_read()
            return self._buffer.readinto(b)
    def readline(self, size=-1):
        """Read a line of uncompressed bytes from the file.
        The terminating newline (if present) is retained. If size is
        non-negative, no more than size bytes will be read (in which
        case the line may be incomplete). Returns b'' if already at EOF.
        """
        if not isinstance(size, int):
            if not hasattr(size, "__index__"):
                raise TypeError("Integer argument expected")
            size = size.__index__()
        with self._lock:
            self._check_can_read()
            return self._buffer.readline(size)
    def readlines(self, size=-1):
        """Read a list of lines of uncompressed bytes from the file.
        size can be specified to control the number of lines read: no
        further lines will be read once the total size of the lines read
        so far equals or exceeds size.
        """
        if not isinstance(size, int):
            if not hasattr(size, "__index__"):
                raise TypeError("Integer argument expected")
            size = size.__index__()
        with self._lock:
            self._check_can_read()
            return self._buffer.readlines(size)
    def write(self, data):
        """Write a byte string to the file.
        Returns the number of uncompressed bytes written, which is
        always len(data). Note that due to buffering, the file on disk
        may not reflect the data written until close() is called.
        """
        with self._lock:
            self._check_can_write()
            compressed = self._compressor.compress(data)
            self._fp.write(compressed)
            self._pos += len(data)
            return len(data)
    def writelines(self, seq):
        """Write a sequence of byte strings to the file.
        Returns the number of uncompressed bytes written.
        seq can be any iterable yielding byte strings.
        Line separators are not added between the written byte strings.
        """
        with self._lock:
            return _compression.BaseStream.writelines(self, seq)
    def seek(self, offset, whence=io.SEEK_SET):
        """Change the file position.
        The new position is specified by offset, relative to the
        position indicated by whence. Values for whence are:
            0: start of stream (default); offset must not be negative
            1: current stream position
            2: end of stream; offset must not be positive
        Returns the new file position.
        Note that seeking is emulated, so depending on the parameters,
        this operation may be extremely slow.
        """
        with self._lock:
            self._check_can_seek()
            return self._buffer.seek(offset, whence)
    def tell(self):
        """Return the current file position."""
        with self._lock:
            self._check_not_closed()
            if self._mode == _MODE_READ:
                return self._buffer.tell()
            return self._pos
 def open(filename, mode="rb", compresslevel=9,
         encoding=None, errors=None, newline=None):
    """Open a bzip2-compressed file in binary or text mode.
    The filename argument can be an actual filename (a str, bytes, or
    PathLike object), or an existing file object to read from or write
    to.
    The mode argument can be "r", "rb", "w", "wb", "x", "xb", "a" or
    "ab" for binary mode, or "rt", "wt", "xt" or "at" for text mode.
    The default mode is "rb", and the default compresslevel is 9.
    For binary mode, this function is equivalent to the BZ2File
    constructor: BZ2File(filename, mode, compresslevel). In this case,
    the encoding, errors and newline arguments must not be provided.
    For text mode, a BZ2File object is created, and wrapped in an
    io.TextIOWrapper instance with the specified encoding, error
    handling behavior, and line ending(s).
    """
    if "t" in mode:
        if "b" in mode:
            raise ValueError("Invalid mode: %r" % (mode,))
    else:
        if encoding is not None:
            raise ValueError("Argument 'encoding' not supported in binary mode")
        if errors is not None:
            raise ValueError("Argument 'errors' not supported in binary mode")
        if newline is not None:
            raise ValueError("Argument 'newline' not supported in binary mode")
    bz_mode = mode.replace("t", "")
    binary_file = BZ2File(filename, bz_mode, compresslevel=compresslevel)
    if "t" in mode:
        return io.TextIOWrapper(binary_file, encoding, errors, newline)
    else:
        return binary_file
 def compress(data, compresslevel=9):
    """Compress a block of data.
    compresslevel, if given, must be a number between 1 and 9.
    For incremental compression, use a BZ2Compressor object instead.
    """
    comp = BZ2Compressor(compresslevel)
    return comp.compress(data) + comp.flush()
 def decompress(data):
    """Decompress a block of data.
    For incremental decompression, use a BZ2Decompressor object instead.
    """
    results = []
    while data:
        decomp = BZ2Decompressor()
        try:
            res = decomp.decompress(data)
        except OSError:
            if results:
                break  # Leftover data is not a valid bzip2 stream; ignore it.
            else:
                raise  # Error on the first iteration; bail out.
        results.append(res)
        if not decomp.eof:
            raise ValueError("Compressed data ended before the "
                             "end-of-stream marker was reached")
        data = decomp.unused_data
    return b"".join(results)
--- a/Lib/cProfile.py
+++ b/Lib/cProfile.py
@ -0,0 +1,173 @@
 #! /usr/bin/env python3
 """Python interface for the 'lsprof' profiler.
   Compatible with the 'profile' module.
 """
 __all__ = ["run", "runctx", "Profile"]
 import _lsprof
 import profile as _pyprofile
 # ____________________________________________________________
 # Simple interface
 def run(statement, filename=None, sort=-1):
    return _pyprofile._Utils(Profile).run(statement, filename, sort)
 def runctx(statement, globals, locals, filename=None, sort=-1):
    return _pyprofile._Utils(Profile).runctx(statement, globals, locals,
                                             filename, sort)
 run.__doc__ = _pyprofile.run.__doc__
 runctx.__doc__ = _pyprofile.runctx.__doc__
 # ____________________________________________________________
 class Profile(_lsprof.Profiler):
    """Profile(timer=None, timeunit=None, subcalls=True, builtins=True)
    Builds a profiler object using the specified timer function.
    The default timer is a fast built-in one based on real time.
    For custom timer functions returning integers, timeunit can
    be a float specifying a scale (i.e. how long each integer unit
    is, in seconds).
    """
    # Most of the functionality is in the base class.
    # This subclass only adds convenient and backward-compatible methods.
    def print_stats(self, sort=-1):
        import pstats
        pstats.Stats(self).strip_dirs().sort_stats(sort).print_stats()
    def dump_stats(self, file):
        import marshal
        with open(file, 'wb') as f:
            self.create_stats()
            marshal.dump(self.stats, f)
    def create_stats(self):
        self.disable()
        self.snapshot_stats()
    def snapshot_stats(self):
        entries = self.getstats()
        self.stats = {}
        callersdicts = {}
        # call information
        for entry in entries:
            func = label(entry.code)
            nc = entry.callcount         # ncalls column of pstats (before '/')
            cc = nc - entry.reccallcount # ncalls column of pstats (after '/')
            tt = entry.inlinetime        # tottime column of pstats
            ct = entry.totaltime         # cumtime column of pstats
            callers = {}
            callersdicts[id(entry.code)] = callers
            self.stats[func] = cc, nc, tt, ct, callers
        # subcall information
        for entry in entries:
            if entry.calls:
                func = label(entry.code)
                for subentry in entry.calls:
                    try:
                        callers = callersdicts[id(subentry.code)]
                    except KeyError:
                        continue
                    nc = subentry.callcount
                    cc = nc - subentry.reccallcount
                    tt = subentry.inlinetime
                    ct = subentry.totaltime
                    if func in callers:
                        prev = callers[func]
                        nc += prev[0]
                        cc += prev[1]
                        tt += prev[2]
                        ct += prev[3]
                    callers[func] = nc, cc, tt, ct
    # The following two methods can be called by clients to use
    # a profiler to profile a statement, given as a string.
    def run(self, cmd):
        import __main__
        dict = __main__.__dict__
        return self.runctx(cmd, dict, dict)
    def runctx(self, cmd, globals, locals):
        self.enable()
        try:
            exec(cmd, globals, locals)
        finally:
            self.disable()
        return self
    # This method is more useful to profile a single function call.
    def runcall(self, func, *args, **kw):
        self.enable()
        try:
            return func(*args, **kw)
        finally:
            self.disable()
 # ____________________________________________________________
 def label(code):
    if isinstance(code, str):
        return ('~', 0, code)    # built-in functions ('~' sorts at the end)
    else:
        return (code.co_filename, code.co_firstlineno, code.co_name)
 # ____________________________________________________________
 def main():
    import os
    import sys
    import runpy
    import pstats
    from optparse import OptionParser
    usage = "cProfile.py [-o output_file_path] [-s sort] [-m module | scriptfile] [arg] ..."
    parser = OptionParser(usage=usage)
    parser.allow_interspersed_args = False
    parser.add_option('-o', '--outfile', dest="outfile",
        help="Save stats to <outfile>", default=None)
    parser.add_option('-s', '--sort', dest="sort",
        help="Sort order when printing to stdout, based on pstats.Stats class",
        default=-1,
        choices=sorted(pstats.Stats.sort_arg_dict_default))
    parser.add_option('-m', dest="module", action="store_true",
        help="Profile a library module", default=False)
    if not sys.argv[1:]:
        parser.print_usage()
        sys.exit(2)
    (options, args) = parser.parse_args()
    sys.argv[:] = args
    if len(args) > 0:
        if options.module:
            code = "run_module(modname, run_name='__main__')"
            globs = {
                'run_module': runpy.run_module,
                'modname': args[0]
            }
        else:
            progname = args[0]
            sys.path.insert(0, os.path.dirname(progname))
            with open(progname, 'rb') as fp:
                code = compile(fp.read(), progname, 'exec')
            globs = {
                '__file__': progname,
                '__name__': '__main__',
                '__package__': None,
                '__cached__': None,
            }
        runctx(code, globs, None, options.outfile, options.sort)
    else:
        parser.print_usage()
    return parser
 # When invoked as main program, invoke the profiler on a script
 if __name__ == '__main__':
    main()
--- a/Lib/calendar.py
+++ b/Lib/calendar.py
@ -0,0 +1,770 @@
 """Calendar printing functions
 Note when comparing these calendars to the ones printed by cal(1): By
 default, these calendars have Monday as the first day of the week, and
 Sunday as the last (the European convention). Use setfirstweekday() to
 set the first day of the week (0=Monday, 6=Sunday)."""
 import sys
 import datetime
 import locale as _locale
 from itertools import repeat
 __all__ = ["IllegalMonthError", "IllegalWeekdayError", "setfirstweekday",
           "firstweekday", "isleap", "leapdays", "weekday", "monthrange",
           "monthcalendar", "prmonth", "month", "prcal", "calendar",
           "timegm", "month_name", "month_abbr", "day_name", "day_abbr",
           "Calendar", "TextCalendar", "HTMLCalendar", "LocaleTextCalendar",
           "LocaleHTMLCalendar", "weekheader"]
 # Exception raised for bad input (with string parameter for details)
 error = ValueError
 # Exceptions raised for bad input
 class IllegalMonthError(ValueError):
    def __init__(self, month):
        self.month = month
    def __str__(self):
        return "bad month number %r; must be 1-12" % self.month
 class IllegalWeekdayError(ValueError):
    def __init__(self, weekday):
        self.weekday = weekday
    def __str__(self):
        return "bad weekday number %r; must be 0 (Monday) to 6 (Sunday)" % self.weekday
 # Constants for months referenced later
 January = 1
 February = 2
 # Number of days per month (except for February in leap years)
 mdays = [0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
 # This module used to have hard-coded lists of day and month names, as
 # English strings.  The classes following emulate a read-only version of
 # that, but supply localized names.  Note that the values are computed
 # fresh on each call, in case the user changes locale between calls.
 class _localized_month:
    _months = [datetime.date(2001, i+1, 1).strftime for i in range(12)]
    _months.insert(0, lambda x: "")
    def __init__(self, format):
        self.format = format
    def __getitem__(self, i):
        funcs = self._months[i]
        if isinstance(i, slice):
            return [f(self.format) for f in funcs]
        else:
            return funcs(self.format)
    def __len__(self):
        return 13
 class _localized_day:
    # January 1, 2001, was a Monday.
    _days = [datetime.date(2001, 1, i+1).strftime for i in range(7)]
    def __init__(self, format):
        self.format = format
    def __getitem__(self, i):
        funcs = self._days[i]
        if isinstance(i, slice):
            return [f(self.format) for f in funcs]
        else:
            return funcs(self.format)
    def __len__(self):
        return 7
 # Full and abbreviated names of weekdays
 day_name = _localized_day('%A')
 day_abbr = _localized_day('%a')
 # Full and abbreviated names of months (1-based arrays!!!)
 month_name = _localized_month('%B')
 month_abbr = _localized_month('%b')
 # Constants for weekdays
 (MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY) = range(7)
 def isleap(year):
    """Return True for leap years, False for non-leap years."""
    return year % 4 == 0 and (year % 100 != 0 or year % 400 == 0)
 def leapdays(y1, y2):
    """Return number of leap years in range [y1, y2).
       Assume y1 <= y2."""
    y1 -= 1
    y2 -= 1
    return (y2//4 - y1//4) - (y2//100 - y1//100) + (y2//400 - y1//400)
 def weekday(year, month, day):
    """Return weekday (0-6 ~ Mon-Sun) for year, month (1-12), day (1-31)."""
    if not datetime.MINYEAR <= year <= datetime.MAXYEAR:
        year = 2000 + year % 400
    return datetime.date(year, month, day).weekday()
 def monthrange(year, month):
    """Return weekday (0-6 ~ Mon-Sun) and number of days (28-31) for
       year, month."""
    if not 1 <= month <= 12:
        raise IllegalMonthError(month)
    day1 = weekday(year, month, 1)
    ndays = mdays[month] + (month == February and isleap(year))
    return day1, ndays
 def monthlen(year, month):
    return mdays[month] + (month == February and isleap(year))
 def prevmonth(year, month):
    if month == 1:
        return year-1, 12
    else:
        return year, month-1
 def nextmonth(year, month):
    if month == 12:
        return year+1, 1
    else:
        return year, month+1
 class Calendar(object):
    """
    Base calendar class. This class doesn't do any formatting. It simply
    provides data to subclasses.
    """
    def __init__(self, firstweekday=0):
        self.firstweekday = firstweekday # 0 = Monday, 6 = Sunday
    def getfirstweekday(self):
        return self._firstweekday % 7
    def setfirstweekday(self, firstweekday):
        self._firstweekday = firstweekday
    firstweekday = property(getfirstweekday, setfirstweekday)
    def iterweekdays(self):
        """
        Return an iterator for one week of weekday numbers starting with the
        configured first one.
        """
        for i in range(self.firstweekday, self.firstweekday + 7):
            yield i%7
    def itermonthdates(self, year, month):
        """
        Return an iterator for one month. The iterator will yield datetime.date
        values and will always iterate through complete weeks, so it will yield
        dates outside the specified month.
        """
        for y, m, d in self.itermonthdays3(year, month):
            yield datetime.date(y, m, d)
    def itermonthdays(self, year, month):
        """
        Like itermonthdates(), but will yield day numbers. For days outside
        the specified month the day number is 0.
        """
        day1, ndays = monthrange(year, month)
        days_before = (day1 - self.firstweekday) % 7
        yield from repeat(0, days_before)
        yield from range(1, ndays + 1)
        days_after = (self.firstweekday - day1 - ndays) % 7
        yield from repeat(0, days_after)
    def itermonthdays2(self, year, month):
        """
        Like itermonthdates(), but will yield (day number, weekday number)
        tuples. For days outside the specified month the day number is 0.
        """
        for i, d in enumerate(self.itermonthdays(year, month), self.firstweekday):
            yield d, i % 7
    def itermonthdays3(self, year, month):
        """
        Like itermonthdates(), but will yield (year, month, day) tuples.  Can be
        used for dates outside of datetime.date range.
        """
        day1, ndays = monthrange(year, month)
        days_before = (day1 - self.firstweekday) % 7
        days_after = (self.firstweekday - day1 - ndays) % 7
        y, m = prevmonth(year, month)
        end = monthlen(y, m) + 1
        for d in range(end-days_before, end):
            yield y, m, d
        for d in range(1, ndays + 1):
            yield year, month, d
        y, m = nextmonth(year, month)
        for d in range(1, days_after + 1):
            yield y, m, d
    def itermonthdays4(self, year, month):
        """
        Like itermonthdates(), but will yield (year, month, day, day_of_week) tuples.
        Can be used for dates outside of datetime.date range.
        """
        for i, (y, m, d) in enumerate(self.itermonthdays3(year, month)):
            yield y, m, d, (self.firstweekday + i) % 7
    def monthdatescalendar(self, year, month):
        """
        Return a matrix (list of lists) representing a month's calendar.
        Each row represents a week; week entries are datetime.date values.
        """
        dates = list(self.itermonthdates(year, month))
        return [ dates[i:i+7] for i in range(0, len(dates), 7) ]
    def monthdays2calendar(self, year, month):
        """
        Return a matrix representing a month's calendar.
        Each row represents a week; week entries are
        (day number, weekday number) tuples. Day numbers outside this month
        are zero.
        """
        days = list(self.itermonthdays2(year, month))
        return [ days[i:i+7] for i in range(0, len(days), 7) ]
    def monthdayscalendar(self, year, month):
        """
        Return a matrix representing a month's calendar.
        Each row represents a week; days outside this month are zero.
        """
        days = list(self.itermonthdays(year, month))
        return [ days[i:i+7] for i in range(0, len(days), 7) ]
    def yeardatescalendar(self, year, width=3):
        """
        Return the data for the specified year ready for formatting. The return
        value is a list of month rows. Each month row contains up to width months.
        Each month contains between 4 and 6 weeks and each week contains 1-7
        days. Days are datetime.date objects.
        """
        months = [
            self.monthdatescalendar(year, i)
            for i in range(January, January+12)
        ]
        return [months[i:i+width] for i in range(0, len(months), width) ]
    def yeardays2calendar(self, year, width=3):
        """
        Return the data for the specified year ready for formatting (similar to
        yeardatescalendar()). Entries in the week lists are
        (day number, weekday number) tuples. Day numbers outside this month are
        zero.
        """
        months = [
            self.monthdays2calendar(year, i)
            for i in range(January, January+12)
        ]
        return [months[i:i+width] for i in range(0, len(months), width) ]
    def yeardayscalendar(self, year, width=3):
        """
        Return the data for the specified year ready for formatting (similar to
        yeardatescalendar()). Entries in the week lists are day numbers.
        Day numbers outside this month are zero.
        """
        months = [
            self.monthdayscalendar(year, i)
            for i in range(January, January+12)
        ]
        return [months[i:i+width] for i in range(0, len(months), width) ]
 class TextCalendar(Calendar):
    """
    Subclass of Calendar that outputs a calendar as a simple plain text
    similar to the UNIX program cal.
    """
    def prweek(self, theweek, width):
        """
        Print a single week (no newline).
        """
        print(self.formatweek(theweek, width), end='')
    def formatday(self, day, weekday, width):
        """
        Returns a formatted day.
        """
        if day == 0:
            s = ''
        else:
            s = '%2i' % day             # right-align single-digit days
        return s.center(width)
    def formatweek(self, theweek, width):
        """
        Returns a single week in a string (no newline).
        """
        return ' '.join(self.formatday(d, wd, width) for (d, wd) in theweek)
    def formatweekday(self, day, width):
        """
        Returns a formatted week day name.
        """
        if width >= 9:
            names = day_name
        else:
            names = day_abbr
        return names[day][:width].center(width)
    def formatweekheader(self, width):
        """
        Return a header for a week.
        """
        return ' '.join(self.formatweekday(i, width) for i in self.iterweekdays())
    def formatmonthname(self, theyear, themonth, width, withyear=True):
        """
        Return a formatted month name.
        """
        s = month_name[themonth]
        if withyear:
            s = "%s %r" % (s, theyear)
        return s.center(width)
    def prmonth(self, theyear, themonth, w=0, l=0):
        """
        Print a month's calendar.
        """
        print(self.formatmonth(theyear, themonth, w, l), end='')
    def formatmonth(self, theyear, themonth, w=0, l=0):
        """
        Return a month's calendar string (multi-line).
        """
        w = max(2, w)
        l = max(1, l)
        s = self.formatmonthname(theyear, themonth, 7 * (w + 1) - 1)
        s = s.rstrip()
        s += '\n' * l
        s += self.formatweekheader(w).rstrip()
        s += '\n' * l
        for week in self.monthdays2calendar(theyear, themonth):
            s += self.formatweek(week, w).rstrip()
            s += '\n' * l
        return s
    def formatyear(self, theyear, w=2, l=1, c=6, m=3):
        """
        Returns a year's calendar as a multi-line string.
        """
        w = max(2, w)
        l = max(1, l)
        c = max(2, c)
        colwidth = (w + 1) * 7 - 1
        v = []
        a = v.append
        a(repr(theyear).center(colwidth*m+c*(m-1)).rstrip())
        a('\n'*l)
        header = self.formatweekheader(w)
        for (i, row) in enumerate(self.yeardays2calendar(theyear, m)):
            # months in this row
            months = range(m*i+1, min(m*(i+1)+1, 13))
            a('\n'*l)
            names = (self.formatmonthname(theyear, k, colwidth, False)
                     for k in months)
            a(formatstring(names, colwidth, c).rstrip())
            a('\n'*l)
            headers = (header for k in months)
            a(formatstring(headers, colwidth, c).rstrip())
            a('\n'*l)
            # max number of weeks for this row
            height = max(len(cal) for cal in row)
            for j in range(height):
                weeks = []
                for cal in row:
                    if j >= len(cal):
                        weeks.append('')
                    else:
                        weeks.append(self.formatweek(cal[j], w))
                a(formatstring(weeks, colwidth, c).rstrip())
                a('\n' * l)
        return ''.join(v)
    def pryear(self, theyear, w=0, l=0, c=6, m=3):
        """Print a year's calendar."""
        print(self.formatyear(theyear, w, l, c, m), end='')
 class HTMLCalendar(Calendar):
    """
    This calendar returns complete HTML pages.
    """
    # CSS classes for the day <td>s
    cssclasses = ["mon", "tue", "wed", "thu", "fri", "sat", "sun"]
    # CSS classes for the day <th>s
    cssclasses_weekday_head = cssclasses
    # CSS class for the days before and after current month
    cssclass_noday = "noday"
    # CSS class for the month's head
    cssclass_month_head = "month"
    # CSS class for the month
    cssclass_month = "month"
    # CSS class for the year's table head
    cssclass_year_head = "year"
    # CSS class for the whole year table
    cssclass_year = "year"
    def formatday(self, day, weekday):
        """
        Return a day as a table cell.
        """
        if day == 0:
            # day outside month
            return '<td class="%s">&nbsp;</td>' % self.cssclass_noday
        else:
            return '<td class="%s">%d</td>' % (self.cssclasses[weekday], day)
    def formatweek(self, theweek):
        """
        Return a complete week as a table row.
        """
        s = ''.join(self.formatday(d, wd) for (d, wd) in theweek)
        return '<tr>%s</tr>' % s
    def formatweekday(self, day):
        """
        Return a weekday name as a table header.
        """
        return '<th class="%s">%s</th>' % (
            self.cssclasses_weekday_head[day], day_abbr[day])
    def formatweekheader(self):
        """
        Return a header for a week as a table row.
        """
        s = ''.join(self.formatweekday(i) for i in self.iterweekdays())
        return '<tr>%s</tr>' % s
    def formatmonthname(self, theyear, themonth, withyear=True):
        """
        Return a month name as a table row.
        """
        if withyear:
            s = '%s %s' % (month_name[themonth], theyear)
        else:
            s = '%s' % month_name[themonth]
        return '<tr><th colspan="7" class="%s">%s</th></tr>' % (
            self.cssclass_month_head, s)
    def formatmonth(self, theyear, themonth, withyear=True):
        """
        Return a formatted month as a table.
        """
        v = []
        a = v.append
        a('<table border="0" cellpadding="0" cellspacing="0" class="%s">' % (
            self.cssclass_month))
        a('\n')
        a(self.formatmonthname(theyear, themonth, withyear=withyear))
        a('\n')
        a(self.formatweekheader())
        a('\n')
        for week in self.monthdays2calendar(theyear, themonth):
            a(self.formatweek(week))
            a('\n')
        a('</table>')
        a('\n')
        return ''.join(v)
    def formatyear(self, theyear, width=3):
        """
        Return a formatted year as a table of tables.
        """
        v = []
        a = v.append
        width = max(width, 1)
        a('<table border="0" cellpadding="0" cellspacing="0" class="%s">' %
          self.cssclass_year)
        a('\n')
        a('<tr><th colspan="%d" class="%s">%s</th></tr>' % (
            width, self.cssclass_year_head, theyear))
        for i in range(January, January+12, width):
            # months in this row
            months = range(i, min(i+width, 13))
            a('<tr>')
            for m in months:
                a('<td>')
                a(self.formatmonth(theyear, m, withyear=False))
                a('</td>')
            a('</tr>')
        a('</table>')
        return ''.join(v)
    def formatyearpage(self, theyear, width=3, css='calendar.css', encoding=None):
        """
        Return a formatted year as a complete HTML page.
        """
        if encoding is None:
            encoding = sys.getdefaultencoding()
        v = []
        a = v.append
        a('<?xml version="1.0" encoding="%s"?>\n' % encoding)
        a('<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">\n')
        a('<html>\n')
        a('<head>\n')
        a('<meta http-equiv="Content-Type" content="text/html; charset=%s" />\n' % encoding)
        if css is not None:
            a('<link rel="stylesheet" type="text/css" href="%s" />\n' % css)
        a('<title>Calendar for %d</title>\n' % theyear)
        a('</head>\n')
        a('<body>\n')
        a(self.formatyear(theyear, width))
        a('</body>\n')
        a('</html>\n')
        return ''.join(v).encode(encoding, "xmlcharrefreplace")
 class different_locale:
    def __init__(self, locale):
        self.locale = locale
    def __enter__(self):
        self.oldlocale = _locale.getlocale(_locale.LC_TIME)
        _locale.setlocale(_locale.LC_TIME, self.locale)
    def __exit__(self, *args):
        _locale.setlocale(_locale.LC_TIME, self.oldlocale)
 class LocaleTextCalendar(TextCalendar):
    """
    This class can be passed a locale name in the constructor and will return
    month and weekday names in the specified locale. If this locale includes
    an encoding all strings containing month and weekday names will be returned
    as unicode.
    """
    def __init__(self, firstweekday=0, locale=None):
        TextCalendar.__init__(self, firstweekday)
        if locale is None:
            locale = _locale.getdefaultlocale()
        self.locale = locale
    def formatweekday(self, day, width):
        with different_locale(self.locale):
            if width >= 9:
                names = day_name
            else:
                names = day_abbr
            name = names[day]
            return name[:width].center(width)
    def formatmonthname(self, theyear, themonth, width, withyear=True):
        with different_locale(self.locale):
            s = month_name[themonth]
            if withyear:
                s = "%s %r" % (s, theyear)
            return s.center(width)
 class LocaleHTMLCalendar(HTMLCalendar):
    """
    This class can be passed a locale name in the constructor and will return
    month and weekday names in the specified locale. If this locale includes
    an encoding all strings containing month and weekday names will be returned
    as unicode.
    """
    def __init__(self, firstweekday=0, locale=None):
        HTMLCalendar.__init__(self, firstweekday)
        if locale is None:
            locale = _locale.getdefaultlocale()
        self.locale = locale
    def formatweekday(self, day):
        with different_locale(self.locale):
            s = day_abbr[day]
            return '<th class="%s">%s</th>' % (self.cssclasses[day], s)
    def formatmonthname(self, theyear, themonth, withyear=True):
        with different_locale(self.locale):
            s = month_name[themonth]
            if withyear:
                s = '%s %s' % (s, theyear)
            return '<tr><th colspan="7" class="month">%s</th></tr>' % s
 # Support for old module level interface
 c = TextCalendar()
 firstweekday = c.getfirstweekday
 def setfirstweekday(firstweekday):
    if not MONDAY <= firstweekday <= SUNDAY:
        raise IllegalWeekdayError(firstweekday)
    c.firstweekday = firstweekday
 monthcalendar = c.monthdayscalendar
 prweek = c.prweek
 week = c.formatweek
 weekheader = c.formatweekheader
 prmonth = c.prmonth
 month = c.formatmonth
 calendar = c.formatyear
 prcal = c.pryear
 # Spacing of month columns for multi-column year calendar
 _colwidth = 7*3 - 1         # Amount printed by prweek()
 _spacing = 6                # Number of spaces between columns
 def format(cols, colwidth=_colwidth, spacing=_spacing):
    """Prints multi-column formatting for year calendars"""
    print(formatstring(cols, colwidth, spacing))
 def formatstring(cols, colwidth=_colwidth, spacing=_spacing):
    """Returns a string formatted from n strings, centered within n columns."""
    spacing *= ' '
    return spacing.join(c.center(colwidth) for c in cols)
 EPOCH = 1970
 _EPOCH_ORD = datetime.date(EPOCH, 1, 1).toordinal()
 def timegm(tuple):
    """Unrelated but handy function to calculate Unix timestamp from GMT."""
    year, month, day, hour, minute, second = tuple[:6]
    days = datetime.date(year, month, 1).toordinal() - _EPOCH_ORD + day - 1
    hours = days*24 + hour
    minutes = hours*60 + minute
    seconds = minutes*60 + second
    return seconds
 def main(args):
    import argparse
    parser = argparse.ArgumentParser()
    textgroup = parser.add_argument_group('text only arguments')
    htmlgroup = parser.add_argument_group('html only arguments')
    textgroup.add_argument(
        "-w", "--width",
        type=int, default=2,
        help="width of date column (default 2)"
    )
    textgroup.add_argument(
        "-l", "--lines",
        type=int, default=1,
        help="number of lines for each week (default 1)"
    )
    textgroup.add_argument(
        "-s", "--spacing",
        type=int, default=6,
        help="spacing between months (default 6)"
    )
    textgroup.add_argument(
        "-m", "--months",
        type=int, default=3,
        help="months per row (default 3)"
    )
    htmlgroup.add_argument(
        "-c", "--css",
        default="calendar.css",
        help="CSS to use for page"
    )
    parser.add_argument(
        "-L", "--locale",
        default=None,
        help="locale to be used from month and weekday names"
    )
    parser.add_argument(
        "-e", "--encoding",
        default=None,
        help="encoding to use for output"
    )
    parser.add_argument(
        "-t", "--type",
        default="text",
        choices=("text", "html"),
        help="output type (text or html)"
    )
    parser.add_argument(
        "year",
        nargs='?', type=int,
        help="year number (1-9999)"
    )
    parser.add_argument(
        "month",
        nargs='?', type=int,
        help="month number (1-12, text only)"
    )
    options = parser.parse_args(args[1:])
    if options.locale and not options.encoding:
        parser.error("if --locale is specified --encoding is required")
        sys.exit(1)
    locale = options.locale, options.encoding
    if options.type == "html":
        if options.locale:
            cal = LocaleHTMLCalendar(locale=locale)
        else:
            cal = HTMLCalendar()
        encoding = options.encoding
        if encoding is None:
            encoding = sys.getdefaultencoding()
        optdict = dict(encoding=encoding, css=options.css)
        write = sys.stdout.buffer.write
        if options.year is None:
            write(cal.formatyearpage(datetime.date.today().year, **optdict))
        elif options.month is None:
            write(cal.formatyearpage(options.year, **optdict))
        else:
            parser.error("incorrect number of arguments")
            sys.exit(1)
    else:
        if options.locale:
            cal = LocaleTextCalendar(locale=locale)
        else:
            cal = TextCalendar()
        optdict = dict(w=options.width, l=options.lines)
        if options.month is None:
            optdict["c"] = options.spacing
            optdict["m"] = options.months
        if options.year is None:
            result = cal.formatyear(datetime.date.today().year, **optdict)
        elif options.month is None:
            result = cal.formatyear(options.year, **optdict)
        else:
            result = cal.formatmonth(options.year, options.month, **optdict)
        write = sys.stdout.write
        if options.encoding:
            result = result.encode(options.encoding)
            write = sys.stdout.buffer.write
        write(result)
 if __name__ == "__main__":
    main(sys.argv)
--- a/Lib/cgi.py
+++ b/Lib/cgi.py
--- a/Lib/cgitb.py
+++ b/Lib/cgitb.py
@ -0,0 +1,319 @@
 """More comprehensive traceback formatting for Python scripts.
 To enable this module, do:
    import cgitb; cgitb.enable()
 at the top of your script.  The optional arguments to enable() are:
    display     - if true, tracebacks are displayed in the web browser
    logdir      - if set, tracebacks are written to files in this directory
    context     - number of lines of source code to show for each stack frame
    format      - 'text' or 'html' controls the output format
 By default, tracebacks are displayed but not saved, the context is 5 lines
 and the output format is 'html' (for backwards compatibility with the
 original use of this module)
 Alternatively, if you have caught an exception and want cgitb to display it
 for you, call cgitb.handler().  The optional argument to handler() is a
 3-item tuple (etype, evalue, etb) just like the value of sys.exc_info().
 The default handler displays output as HTML.
 """
 import inspect
 import keyword
 import linecache
 import os
 import pydoc
 import sys
 import tempfile
 import time
 import tokenize
 import traceback
 def reset():
    """Return a string that resets the CGI and browser to a known state."""
    return '''<!--: spam
 Content-Type: text/html
 <body bgcolor="#f0f0f8"><font color="#f0f0f8" size="-5"> -->
 <body bgcolor="#f0f0f8"><font color="#f0f0f8" size="-5"> --> -->
 </font> </font> </font> </script> </object> </blockquote> </pre>
 </table> </table> </table> </table> </table> </font> </font> </font>'''
 __UNDEF__ = []                          # a special sentinel object
 def small(text):
    if text:
        return '<small>' + text + '</small>'
    else:
        return ''
 def strong(text):
    if text:
        return '<strong>' + text + '</strong>'
    else:
        return ''
 def grey(text):
    if text:
        return '<font color="#909090">' + text + '</font>'
    else:
        return ''
 def lookup(name, frame, locals):
    """Find the value for a given name in the given environment."""
    if name in locals:
        return 'local', locals[name]
    if name in frame.f_globals:
        return 'global', frame.f_globals[name]
    if '__builtins__' in frame.f_globals:
        builtins = frame.f_globals['__builtins__']
        if type(builtins) is type({}):
            if name in builtins:
                return 'builtin', builtins[name]
        else:
            if hasattr(builtins, name):
                return 'builtin', getattr(builtins, name)
    return None, __UNDEF__
 def scanvars(reader, frame, locals):
    """Scan one logical line of Python and look up values of variables used."""
    vars, lasttoken, parent, prefix, value = [], None, None, '', __UNDEF__
    for ttype, token, start, end, line in tokenize.generate_tokens(reader):
        if ttype == tokenize.NEWLINE: break
        if ttype == tokenize.NAME and token not in keyword.kwlist:
            if lasttoken == '.':
                if parent is not __UNDEF__:
                    value = getattr(parent, token, __UNDEF__)
                    vars.append((prefix + token, prefix, value))
            else:
                where, value = lookup(token, frame, locals)
                vars.append((token, where, value))
        elif token == '.':
            prefix += lasttoken + '.'
            parent = value
        else:
            parent, prefix = None, ''
        lasttoken = token
    return vars
 def html(einfo, context=5):
    """Return a nice HTML document describing a given traceback."""
    etype, evalue, etb = einfo
    if isinstance(etype, type):
        etype = etype.__name__
    pyver = 'Python ' + sys.version.split()[0] + ': ' + sys.executable
    date = time.ctime(time.time())
    head = '<body bgcolor="#f0f0f8">' + pydoc.html.heading(
        '<big><big>%s</big></big>' %
        strong(pydoc.html.escape(str(etype))),
        '#ffffff', '#6622aa', pyver + '<br>' + date) + '''
 <p>A problem occurred in a Python script.  Here is the sequence of
 function calls leading up to the error, in the order they occurred.</p>'''
    indent = '<tt>' + small('&nbsp;' * 5) + '&nbsp;</tt>'
    frames = []
    records = inspect.getinnerframes(etb, context)
    for frame, file, lnum, func, lines, index in records:
        if file:
            file = os.path.abspath(file)
            link = '<a href="file://%s">%s</a>' % (file, pydoc.html.escape(file))
        else:
            file = link = '?'
        args, varargs, varkw, locals = inspect.getargvalues(frame)
        call = ''
        if func != '?':
            call = 'in ' + strong(pydoc.html.escape(func)) + \
                inspect.formatargvalues(args, varargs, varkw, locals,
                    formatvalue=lambda value: '=' + pydoc.html.repr(value))
        highlight = {}
        def reader(lnum=[lnum]):
            highlight[lnum[0]] = 1
            try: return linecache.getline(file, lnum[0])
            finally: lnum[0] += 1
        vars = scanvars(reader, frame, locals)
        rows = ['<tr><td bgcolor="#d8bbff">%s%s %s</td></tr>' %
                ('<big>&nbsp;</big>', link, call)]
        if index is not None:
            i = lnum - index
            for line in lines:
                num = small('&nbsp;' * (5-len(str(i))) + str(i)) + '&nbsp;'
                if i in highlight:
                    line = '<tt>=&gt;%s%s</tt>' % (num, pydoc.html.preformat(line))
                    rows.append('<tr><td bgcolor="#ffccee">%s</td></tr>' % line)
                else:
                    line = '<tt>&nbsp;&nbsp;%s%s</tt>' % (num, pydoc.html.preformat(line))
                    rows.append('<tr><td>%s</td></tr>' % grey(line))
                i += 1
        done, dump = {}, []
        for name, where, value in vars:
            if name in done: continue
            done[name] = 1
            if value is not __UNDEF__:
                if where in ('global', 'builtin'):
                    name = ('<em>%s</em> ' % where) + strong(name)
                elif where == 'local':
                    name = strong(name)
                else:
                    name = where + strong(name.split('.')[-1])
                dump.append('%s&nbsp;= %s' % (name, pydoc.html.repr(value)))
            else:
                dump.append(name + ' <em>undefined</em>')
        rows.append('<tr><td>%s</td></tr>' % small(grey(', '.join(dump))))
        frames.append('''
 <table width="100%%" cellspacing=0 cellpadding=0 border=0>
 %s</table>''' % '\n'.join(rows))
    exception = ['<p>%s: %s' % (strong(pydoc.html.escape(str(etype))),
                                pydoc.html.escape(str(evalue)))]
    for name in dir(evalue):
        if name[:1] == '_': continue
        value = pydoc.html.repr(getattr(evalue, name))
        exception.append('\n<br>%s%s&nbsp;=\n%s' % (indent, name, value))
    return head + ''.join(frames) + ''.join(exception) + '''
 <!-- The above is a description of an error in a Python program, formatted
     for a Web browser because the 'cgitb' module was enabled.  In case you
     are not reading this in a Web browser, here is the original traceback:
 %s
 -->
 ''' % pydoc.html.escape(
          ''.join(traceback.format_exception(etype, evalue, etb)))
 def text(einfo, context=5):
    """Return a plain text document describing a given traceback."""
    etype, evalue, etb = einfo
    if isinstance(etype, type):
        etype = etype.__name__
    pyver = 'Python ' + sys.version.split()[0] + ': ' + sys.executable
    date = time.ctime(time.time())
    head = "%s\n%s\n%s\n" % (str(etype), pyver, date) + '''
 A problem occurred in a Python script.  Here is the sequence of
 function calls leading up to the error, in the order they occurred.
 '''
    frames = []
    records = inspect.getinnerframes(etb, context)
    for frame, file, lnum, func, lines, index in records:
        file = file and os.path.abspath(file) or '?'
        args, varargs, varkw, locals = inspect.getargvalues(frame)
        call = ''
        if func != '?':
            call = 'in ' + func + \
                inspect.formatargvalues(args, varargs, varkw, locals,
                    formatvalue=lambda value: '=' + pydoc.text.repr(value))
        highlight = {}
        def reader(lnum=[lnum]):
            highlight[lnum[0]] = 1
            try: return linecache.getline(file, lnum[0])
            finally: lnum[0] += 1
        vars = scanvars(reader, frame, locals)
        rows = [' %s %s' % (file, call)]
        if index is not None:
            i = lnum - index
            for line in lines:
                num = '%5d ' % i
                rows.append(num+line.rstrip())
                i += 1
        done, dump = {}, []
        for name, where, value in vars:
            if name in done: continue
            done[name] = 1
            if value is not __UNDEF__:
                if where == 'global': name = 'global ' + name
                elif where != 'local': name = where + name.split('.')[-1]
                dump.append('%s = %s' % (name, pydoc.text.repr(value)))
            else:
                dump.append(name + ' undefined')
        rows.append('\n'.join(dump))
        frames.append('\n%s\n' % '\n'.join(rows))
    exception = ['%s: %s' % (str(etype), str(evalue))]
    for name in dir(evalue):
        value = pydoc.text.repr(getattr(evalue, name))
        exception.append('\n%s%s = %s' % (" "*4, name, value))
    return head + ''.join(frames) + ''.join(exception) + '''
 The above is a description of an error in a Python program.  Here is
 the original traceback:
 %s
 ''' % ''.join(traceback.format_exception(etype, evalue, etb))
 class Hook:
    """A hook to replace sys.excepthook that shows tracebacks in HTML."""
    def __init__(self, display=1, logdir=None, context=5, file=None,
                 format="html"):
        self.display = display          # send tracebacks to browser if true
        self.logdir = logdir            # log tracebacks to files if not None
        self.context = context          # number of source code lines per frame
        self.file = file or sys.stdout  # place to send the output
        self.format = format
    def __call__(self, etype, evalue, etb):
        self.handle((etype, evalue, etb))
    def handle(self, info=None):
        info = info or sys.exc_info()
        if self.format == "html":
            self.file.write(reset())
        formatter = (self.format=="html") and html or text
        plain = False
        try:
            doc = formatter(info, self.context)
        except:                         # just in case something goes wrong
            doc = ''.join(traceback.format_exception(*info))
            plain = True
        if self.display:
            if plain:
                doc = pydoc.html.escape(doc)
                self.file.write('<pre>' + doc + '</pre>\n')
            else:
                self.file.write(doc + '\n')
        else:
            self.file.write('<p>A problem occurred in a Python script.\n')
        if self.logdir is not None:
            suffix = ['.txt', '.html'][self.format=="html"]
            (fd, path) = tempfile.mkstemp(suffix=suffix, dir=self.logdir)
            try:
                with os.fdopen(fd, 'w') as file:
                    file.write(doc)
                msg = '%s contains the description of this error.' % path
            except:
                msg = 'Tried to save traceback to %s, but failed.' % path
            if self.format == 'html':
                self.file.write('<p>%s</p>\n' % msg)
            else:
                self.file.write(msg + '\n')
        try:
            self.file.flush()
        except: pass
 handler = Hook().handle
 def enable(display=1, logdir=None, context=5, format="html"):
    """Install an exception handler that formats tracebacks as HTML.
    The optional argument 'display' can be set to 0 to suppress sending the
    traceback to the browser, and 'logdir' can be set to a directory to cause
    tracebacks to be written to files there."""
    sys.excepthook = Hook(display=display, logdir=logdir,
                          context=context, format=format)
--- a/Lib/chunk.py
+++ b/Lib/chunk.py
@ -0,0 +1,169 @@
 """Simple class to read IFF chunks.
 An IFF chunk (used in formats such as AIFF, TIFF, RMFF (RealMedia File
 Format)) has the following structure:
 +----------------+
 | ID (4 bytes)   |
 +----------------+
 | size (4 bytes) |
 +----------------+
 | data           |
 | ...            |
 +----------------+
 The ID is a 4-byte string which identifies the type of chunk.
 The size field (a 32-bit value, encoded using big-endian byte order)
 gives the size of the whole chunk, including the 8-byte header.
 Usually an IFF-type file consists of one or more chunks.  The proposed
 usage of the Chunk class defined here is to instantiate an instance at
 the start of each chunk and read from the instance until it reaches
 the end, after which a new instance can be instantiated.  At the end
 of the file, creating a new instance will fail with an EOFError
 exception.
 Usage:
 while True:
    try:
        chunk = Chunk(file)
    except EOFError:
        break
    chunktype = chunk.getname()
    while True:
        data = chunk.read(nbytes)
        if not data:
            pass
        # do something with data
 The interface is file-like.  The implemented methods are:
 read, close, seek, tell, isatty.
 Extra methods are: skip() (called by close, skips to the end of the chunk),
 getname() (returns the name (ID) of the chunk)
 The __init__ method has one required argument, a file-like object
 (including a chunk instance), and one optional argument, a flag which
 specifies whether or not chunks are aligned on 2-byte boundaries.  The
 default is 1, i.e. aligned.
 """
 class Chunk:
    def __init__(self, file, align=True, bigendian=True, inclheader=False):
        import struct
        self.closed = False
        self.align = align      # whether to align to word (2-byte) boundaries
        if bigendian:
            strflag = '>'
        else:
            strflag = '<'
        self.file = file
        self.chunkname = file.read(4)
        if len(self.chunkname) < 4:
            raise EOFError
        try:
            self.chunksize = struct.unpack_from(strflag+'L', file.read(4))[0]
        except struct.error:
            raise EOFError from None
        if inclheader:
            self.chunksize = self.chunksize - 8 # subtract header
        self.size_read = 0
        try:
            self.offset = self.file.tell()
        except (AttributeError, OSError):
            self.seekable = False
        else:
            self.seekable = True
    def getname(self):
        """Return the name (ID) of the current chunk."""
        return self.chunkname
    def getsize(self):
        """Return the size of the current chunk."""
        return self.chunksize
    def close(self):
        if not self.closed:
            try:
                self.skip()
            finally:
                self.closed = True
    def isatty(self):
        if self.closed:
            raise ValueError("I/O operation on closed file")
        return False
    def seek(self, pos, whence=0):
        """Seek to specified position into the chunk.
        Default position is 0 (start of chunk).
        If the file is not seekable, this will result in an error.
        """
        if self.closed:
            raise ValueError("I/O operation on closed file")
        if not self.seekable:
            raise OSError("cannot seek")
        if whence == 1:
            pos = pos + self.size_read
        elif whence == 2:
            pos = pos + self.chunksize
        if pos < 0 or pos > self.chunksize:
            raise RuntimeError
        self.file.seek(self.offset + pos, 0)
        self.size_read = pos
    def tell(self):
        if self.closed:
            raise ValueError("I/O operation on closed file")
        return self.size_read
    def read(self, size=-1):
        """Read at most size bytes from the chunk.
        If size is omitted or negative, read until the end
        of the chunk.
        """
        if self.closed:
            raise ValueError("I/O operation on closed file")
        if self.size_read >= self.chunksize:
            return b''
        if size < 0:
            size = self.chunksize - self.size_read
        if size > self.chunksize - self.size_read:
            size = self.chunksize - self.size_read
        data = self.file.read(size)
        self.size_read = self.size_read + len(data)
        if self.size_read == self.chunksize and \
           self.align and \
           (self.chunksize & 1):
            dummy = self.file.read(1)
            self.size_read = self.size_read + len(dummy)
        return data
    def skip(self):
        """Skip the rest of the chunk.
        If you are not interested in the contents of the chunk,
        this method should be called so that the file points to
        the start of the next chunk.
        """
        if self.closed:
            raise ValueError("I/O operation on closed file")
        if self.seekable:
            try:
                n = self.chunksize - self.size_read
                # maybe fix alignment
                if self.align and (self.chunksize & 1):
                    n = n + 1
                self.file.seek(n, 1)
                self.size_read = self.size_read + n
                return
            except OSError:
                pass
        while self.size_read < self.chunksize:
            n = min(8192, self.chunksize - self.size_read)
            dummy = self.read(n)
            if not dummy:
                raise EOFError
--- a/Lib/cmd.py
+++ b/Lib/cmd.py
@ -0,0 +1,401 @@
 """A generic class to build line-oriented command interpreters.
 Interpreters constructed with this class obey the following conventions:
 1. End of file on input is processed as the command 'EOF'.
 2. A command is parsed out of each line by collecting the prefix composed
   of characters in the identchars member.
 3. A command `foo' is dispatched to a method 'do_foo()'; the do_ method
   is passed a single argument consisting of the remainder of the line.
 4. Typing an empty line repeats the last command.  (Actually, it calls the
   method `emptyline', which may be overridden in a subclass.)
 5. There is a predefined `help' method.  Given an argument `topic', it
   calls the command `help_topic'.  With no arguments, it lists all topics
   with defined help_ functions, broken into up to three topics; documented
   commands, miscellaneous help topics, and undocumented commands.
 6. The command '?' is a synonym for `help'.  The command '!' is a synonym
   for `shell', if a do_shell method exists.
 7. If completion is enabled, completing commands will be done automatically,
   and completing of commands args is done by calling complete_foo() with
   arguments text, line, begidx, endidx.  text is string we are matching
   against, all returned matches must begin with it.  line is the current
   input line (lstripped), begidx and endidx are the beginning and end
   indexes of the text being matched, which could be used to provide
   different completion depending upon which position the argument is in.
 The `default' method may be overridden to intercept commands for which there
 is no do_ method.
 The `completedefault' method may be overridden to intercept completions for
 commands that have no complete_ method.
 The data member `self.ruler' sets the character used to draw separator lines
 in the help messages.  If empty, no ruler line is drawn.  It defaults to "=".
 If the value of `self.intro' is nonempty when the cmdloop method is called,
 it is printed out on interpreter startup.  This value may be overridden
 via an optional argument to the cmdloop() method.
 The data members `self.doc_header', `self.misc_header', and
 `self.undoc_header' set the headers used for the help function's
 listings of documented functions, miscellaneous topics, and undocumented
 functions respectively.
 """
 import string, sys
 __all__ = ["Cmd"]
 PROMPT = '(Cmd) '
 IDENTCHARS = string.ascii_letters + string.digits + '_'
 class Cmd:
    """A simple framework for writing line-oriented command interpreters.
    These are often useful for test harnesses, administrative tools, and
    prototypes that will later be wrapped in a more sophisticated interface.
    A Cmd instance or subclass instance is a line-oriented interpreter
    framework.  There is no good reason to instantiate Cmd itself; rather,
    it's useful as a superclass of an interpreter class you define yourself
    in order to inherit Cmd's methods and encapsulate action methods.
    """
    prompt = PROMPT
    identchars = IDENTCHARS
    ruler = '='
    lastcmd = ''
    intro = None
    doc_leader = ""
    doc_header = "Documented commands (type help <topic>):"
    misc_header = "Miscellaneous help topics:"
    undoc_header = "Undocumented commands:"
    nohelp = "*** No help on %s"
    use_rawinput = 1
    def __init__(self, completekey='tab', stdin=None, stdout=None):
        """Instantiate a line-oriented interpreter framework.
        The optional argument 'completekey' is the readline name of a
        completion key; it defaults to the Tab key. If completekey is
        not None and the readline module is available, command completion
        is done automatically. The optional arguments stdin and stdout
        specify alternate input and output file objects; if not specified,
        sys.stdin and sys.stdout are used.
        """
        if stdin is not None:
            self.stdin = stdin
        else:
            self.stdin = sys.stdin
        if stdout is not None:
            self.stdout = stdout
        else:
            self.stdout = sys.stdout
        self.cmdqueue = []
        self.completekey = completekey
    def cmdloop(self, intro=None):
        """Repeatedly issue a prompt, accept input, parse an initial prefix
        off the received input, and dispatch to action methods, passing them
        the remainder of the line as argument.
        """
        self.preloop()
        if self.use_rawinput and self.completekey:
            try:
                import readline
                self.old_completer = readline.get_completer()
                readline.set_completer(self.complete)
                readline.parse_and_bind(self.completekey+": complete")
            except ImportError:
                pass
        try:
            if intro is not None:
                self.intro = intro
            if self.intro:
                self.stdout.write(str(self.intro)+"\n")
            stop = None
            while not stop:
                if self.cmdqueue:
                    line = self.cmdqueue.pop(0)
                else:
                    if self.use_rawinput:
                        try:
                            line = input(self.prompt)
                        except EOFError:
                            line = 'EOF'
                    else:
                        self.stdout.write(self.prompt)
                        self.stdout.flush()
                        line = self.stdin.readline()
                        if not len(line):
                            line = 'EOF'
                        else:
                            line = line.rstrip('\r\n')
                line = self.precmd(line)
                stop = self.onecmd(line)
                stop = self.postcmd(stop, line)
            self.postloop()
        finally:
            if self.use_rawinput and self.completekey:
                try:
                    import readline
                    readline.set_completer(self.old_completer)
                except ImportError:
                    pass
    def precmd(self, line):
        """Hook method executed just before the command line is
        interpreted, but after the input prompt is generated and issued.
        """
        return line
    def postcmd(self, stop, line):
        """Hook method executed just after a command dispatch is finished."""
        return stop
    def preloop(self):
        """Hook method executed once when the cmdloop() method is called."""
        pass
    def postloop(self):
        """Hook method executed once when the cmdloop() method is about to
        return.
        """
        pass
    def parseline(self, line):
        """Parse the line into a command name and a string containing
        the arguments.  Returns a tuple containing (command, args, line).
        'command' and 'args' may be None if the line couldn't be parsed.
        """
        line = line.strip()
        if not line:
            return None, None, line
        elif line[0] == '?':
            line = 'help ' + line[1:]
        elif line[0] == '!':
            if hasattr(self, 'do_shell'):
                line = 'shell ' + line[1:]
            else:
                return None, None, line
        i, n = 0, len(line)
        while i < n and line[i] in self.identchars: i = i+1
        cmd, arg = line[:i], line[i:].strip()
        return cmd, arg, line
    def onecmd(self, line):
        """Interpret the argument as though it had been typed in response
        to the prompt.
        This may be overridden, but should not normally need to be;
        see the precmd() and postcmd() methods for useful execution hooks.
        The return value is a flag indicating whether interpretation of
        commands by the interpreter should stop.
        """
        cmd, arg, line = self.parseline(line)
        if not line:
            return self.emptyline()
        if cmd is None:
            return self.default(line)
        self.lastcmd = line
        if line == 'EOF' :
            self.lastcmd = ''
        if cmd == '':
            return self.default(line)
        else:
            try:
                func = getattr(self, 'do_' + cmd)
            except AttributeError:
                return self.default(line)
            return func(arg)
    def emptyline(self):
        """Called when an empty line is entered in response to the prompt.
        If this method is not overridden, it repeats the last nonempty
        command entered.
        """
        if self.lastcmd:
            return self.onecmd(self.lastcmd)
    def default(self, line):
        """Called on an input line when the command prefix is not recognized.
        If this method is not overridden, it prints an error message and
        returns.
        """
        self.stdout.write('*** Unknown syntax: %s\n'%line)
    def completedefault(self, *ignored):
        """Method called to complete an input line when no command-specific
        complete_*() method is available.
        By default, it returns an empty list.
        """
        return []
    def completenames(self, text, *ignored):
        dotext = 'do_'+text
        return [a[3:] for a in self.get_names() if a.startswith(dotext)]
    def complete(self, text, state):
        """Return the next possible completion for 'text'.
        If a command has not been entered, then complete against command list.
        Otherwise try to call complete_<command> to get list of completions.
        """
        if state == 0:
            import readline
            origline = readline.get_line_buffer()
            line = origline.lstrip()
            stripped = len(origline) - len(line)
            begidx = readline.get_begidx() - stripped
            endidx = readline.get_endidx() - stripped
            if begidx>0:
                cmd, args, foo = self.parseline(line)
                if cmd == '':
                    compfunc = self.completedefault
                else:
                    try:
                        compfunc = getattr(self, 'complete_' + cmd)
                    except AttributeError:
                        compfunc = self.completedefault
            else:
                compfunc = self.completenames
            self.completion_matches = compfunc(text, line, begidx, endidx)
        try:
            return self.completion_matches[state]
        except IndexError:
            return None
    def get_names(self):
        # This method used to pull in base class attributes
        # at a time dir() didn't do it yet.
        return dir(self.__class__)
    def complete_help(self, *args):
        commands = set(self.completenames(*args))
        topics = set(a[5:] for a in self.get_names()
                     if a.startswith('help_' + args[0]))
        return list(commands | topics)
    def do_help(self, arg):
        'List available commands with "help" or detailed help with "help cmd".'
        if arg:
            # XXX check arg syntax
            try:
                func = getattr(self, 'help_' + arg)
            except AttributeError:
                try:
                    doc=getattr(self, 'do_' + arg).__doc__
                    if doc:
                        self.stdout.write("%s\n"%str(doc))
                        return
                except AttributeError:
                    pass
                self.stdout.write("%s\n"%str(self.nohelp % (arg,)))
                return
            func()
        else:
            names = self.get_names()
            cmds_doc = []
            cmds_undoc = []
            help = {}
            for name in names:
                if name[:5] == 'help_':
                    help[name[5:]]=1
            names.sort()
            # There can be duplicates if routines overridden
            prevname = ''
            for name in names:
                if name[:3] == 'do_':
                    if name == prevname:
                        continue
                    prevname = name
                    cmd=name[3:]
                    if cmd in help:
                        cmds_doc.append(cmd)
                        del help[cmd]
                    elif getattr(self, name).__doc__:
                        cmds_doc.append(cmd)
                    else:
                        cmds_undoc.append(cmd)
            self.stdout.write("%s\n"%str(self.doc_leader))
            self.print_topics(self.doc_header,   cmds_doc,   15,80)
            self.print_topics(self.misc_header,  list(help.keys()),15,80)
            self.print_topics(self.undoc_header, cmds_undoc, 15,80)
    def print_topics(self, header, cmds, cmdlen, maxcol):
        if cmds:
            self.stdout.write("%s\n"%str(header))
            if self.ruler:
                self.stdout.write("%s\n"%str(self.ruler * len(header)))
            self.columnize(cmds, maxcol-1)
            self.stdout.write("\n")
    def columnize(self, list, displaywidth=80):
        """Display a list of strings as a compact set of columns.
        Each column is only as wide as necessary.
        Columns are separated by two spaces (one was not legible enough).
        """
        if not list:
            self.stdout.write("<empty>\n")
            return
        nonstrings = [i for i in range(len(list))
                        if not isinstance(list[i], str)]
        if nonstrings:
            raise TypeError("list[i] not a string for i in %s"
                            % ", ".join(map(str, nonstrings)))
        size = len(list)
        if size == 1:
            self.stdout.write('%s\n'%str(list[0]))
            return
        # Try every row count from 1 upwards
        for nrows in range(1, len(list)):
            ncols = (size+nrows-1) // nrows
            colwidths = []
            totwidth = -2
            for col in range(ncols):
                colwidth = 0
                for row in range(nrows):
                    i = row + nrows*col
                    if i >= size:
                        break
                    x = list[i]
                    colwidth = max(colwidth, len(x))
                colwidths.append(colwidth)
                totwidth += colwidth + 2
                if totwidth > displaywidth:
                    break
            if totwidth <= displaywidth:
                break
        else:
            nrows = len(list)
            ncols = 1
            colwidths = [0]
        for row in range(nrows):
            texts = []
            for col in range(ncols):
                i = row + nrows*col
                if i >= size:
                    x = ""
                else:
                    x = list[i]
                texts.append(x)
            while texts and not texts[-1]:
                del texts[-1]
            for col in range(len(texts)):
                texts[col] = texts[col].ljust(colwidths[col])
            self.stdout.write("%s\n"%str("  ".join(texts)))
--- a/Lib/code.py
+++ b/Lib/code.py
@ -0,0 +1,315 @@
 """Utilities needed to emulate Python's interactive interpreter.
 """
 # Inspired by similar code by Jeff Epler and Fredrik Lundh.
 import sys
 import traceback
 from codeop import CommandCompiler, compile_command
 __all__ = ["InteractiveInterpreter", "InteractiveConsole", "interact",
           "compile_command"]
 class InteractiveInterpreter:
    """Base class for InteractiveConsole.
    This class deals with parsing and interpreter state (the user's
    namespace); it doesn't deal with input buffering or prompting or
    input file naming (the filename is always passed in explicitly).
    """
    def __init__(self, locals=None):
        """Constructor.
        The optional 'locals' argument specifies the dictionary in
        which code will be executed; it defaults to a newly created
        dictionary with key "__name__" set to "__console__" and key
        "__doc__" set to None.
        """
        if locals is None:
            locals = {"__name__": "__console__", "__doc__": None}
        self.locals = locals
        self.compile = CommandCompiler()
    def runsource(self, source, filename="<input>", symbol="single"):
        """Compile and run some source in the interpreter.
        Arguments are as for compile_command().
        One several things can happen:
        1) The input is incorrect; compile_command() raised an
        exception (SyntaxError or OverflowError).  A syntax traceback
        will be printed by calling the showsyntaxerror() method.
        2) The input is incomplete, and more input is required;
        compile_command() returned None.  Nothing happens.
        3) The input is complete; compile_command() returned a code
        object.  The code is executed by calling self.runcode() (which
        also handles run-time exceptions, except for SystemExit).
        The return value is True in case 2, False in the other cases (unless
        an exception is raised).  The return value can be used to
        decide whether to use sys.ps1 or sys.ps2 to prompt the next
        line.
        """
        try:
            code = self.compile(source, filename, symbol)
        except (OverflowError, SyntaxError, ValueError):
            # Case 1
            self.showsyntaxerror(filename)
            return False
        if code is None:
            # Case 2
            return True
        # Case 3
        self.runcode(code)
        return False
    def runcode(self, code):
        """Execute a code object.
        When an exception occurs, self.showtraceback() is called to
        display a traceback.  All exceptions are caught except
        SystemExit, which is reraised.
        A note about KeyboardInterrupt: this exception may occur
        elsewhere in this code, and may not always be caught.  The
        caller should be prepared to deal with it.
        """
        try:
            exec(code, self.locals)
        except SystemExit:
            raise
        except:
            self.showtraceback()
    def showsyntaxerror(self, filename=None):
        """Display the syntax error that just occurred.
        This doesn't display a stack trace because there isn't one.
        If a filename is given, it is stuffed in the exception instead
        of what was there before (because Python's parser always uses
        "<string>" when reading from a string).
        The output is written by self.write(), below.
        """
        type, value, tb = sys.exc_info()
        sys.last_type = type
        sys.last_value = value
        sys.last_traceback = tb
        if filename and type is SyntaxError:
            # Work hard to stuff the correct filename in the exception
            try:
                msg, (dummy_filename, lineno, offset, line) = value.args
            except ValueError:
                # Not the format we expect; leave it alone
                pass
            else:
                # Stuff in the right filename
                value = SyntaxError(msg, (filename, lineno, offset, line))
                sys.last_value = value
        if sys.excepthook is sys.__excepthook__:
            lines = traceback.format_exception_only(type, value)
            self.write(''.join(lines))
        else:
            # If someone has set sys.excepthook, we let that take precedence
            # over self.write
            sys.excepthook(type, value, tb)
    def showtraceback(self):
        """Display the exception that just occurred.
        We remove the first stack item because it is our own code.
        The output is written by self.write(), below.
        """
        sys.last_type, sys.last_value, last_tb = ei = sys.exc_info()
        sys.last_traceback = last_tb
        try:
            lines = traceback.format_exception(ei[0], ei[1], last_tb.tb_next)
            if sys.excepthook is sys.__excepthook__:
                self.write(''.join(lines))
            else:
                # If someone has set sys.excepthook, we let that take precedence
                # over self.write
                sys.excepthook(ei[0], ei[1], last_tb)
        finally:
            last_tb = ei = None
    def write(self, data):
        """Write a string.
        The base implementation writes to sys.stderr; a subclass may
        replace this with a different implementation.
        """
        sys.stderr.write(data)
 class InteractiveConsole(InteractiveInterpreter):
    """Closely emulate the behavior of the interactive Python interpreter.
    This class builds on InteractiveInterpreter and adds prompting
    using the familiar sys.ps1 and sys.ps2, and input buffering.
    """
    def __init__(self, locals=None, filename="<console>"):
        """Constructor.
        The optional locals argument will be passed to the
        InteractiveInterpreter base class.
        The optional filename argument should specify the (file)name
        of the input stream; it will show up in tracebacks.
        """
        InteractiveInterpreter.__init__(self, locals)
        self.filename = filename
        self.resetbuffer()
    def resetbuffer(self):
        """Reset the input buffer."""
        self.buffer = []
    def interact(self, banner=None, exitmsg=None):
        """Closely emulate the interactive Python console.
        The optional banner argument specifies the banner to print
        before the first interaction; by default it prints a banner
        similar to the one printed by the real Python interpreter,
        followed by the current class name in parentheses (so as not
        to confuse this with the real interpreter -- since it's so
        close!).
        The optional exitmsg argument specifies the exit message
        printed when exiting. Pass the empty string to suppress
        printing an exit message. If exitmsg is not given or None,
        a default message is printed.
        """
        try:
            sys.ps1
        except AttributeError:
            sys.ps1 = ">>> "
        try:
            sys.ps2
        except AttributeError:
            sys.ps2 = "... "
        cprt = 'Type "help", "copyright", "credits" or "license" for more information.'
        if banner is None:
            self.write("Python %s on %s\n%s\n(%s)\n" %
                       (sys.version, sys.platform, cprt,
                        self.__class__.__name__))
        elif banner:
            self.write("%s\n" % str(banner))
        more = 0
        while 1:
            try:
                if more:
                    prompt = sys.ps2
                else:
                    prompt = sys.ps1
                try:
                    line = self.raw_input(prompt)
                except EOFError:
                    self.write("\n")
                    break
                else:
                    more = self.push(line)
            except KeyboardInterrupt:
                self.write("\nKeyboardInterrupt\n")
                self.resetbuffer()
                more = 0
        if exitmsg is None:
            self.write('now exiting %s...\n' % self.__class__.__name__)
        elif exitmsg != '':
            self.write('%s\n' % exitmsg)
    def push(self, line):
        """Push a line to the interpreter.
        The line should not have a trailing newline; it may have
        internal newlines.  The line is appended to a buffer and the
        interpreter's runsource() method is called with the
        concatenated contents of the buffer as source.  If this
        indicates that the command was executed or invalid, the buffer
        is reset; otherwise, the command is incomplete, and the buffer
        is left as it was after the line was appended.  The return
        value is 1 if more input is required, 0 if the line was dealt
        with in some way (this is the same as runsource()).
        """
        self.buffer.append(line)
        source = "\n".join(self.buffer)
        more = self.runsource(source, self.filename)
        if not more:
            self.resetbuffer()
        return more
    def raw_input(self, prompt=""):
        """Write a prompt and read a line.
        The returned line does not include the trailing newline.
        When the user enters the EOF key sequence, EOFError is raised.
        The base implementation uses the built-in function
        input(); a subclass may replace this with a different
        implementation.
        """
        return input(prompt)
 def interact(banner=None, readfunc=None, local=None, exitmsg=None):
    """Closely emulate the interactive Python interpreter.
    This is a backwards compatible interface to the InteractiveConsole
    class.  When readfunc is not specified, it attempts to import the
    readline module to enable GNU readline if it is available.
    Arguments (all optional, all default to None):
    banner -- passed to InteractiveConsole.interact()
    readfunc -- if not None, replaces InteractiveConsole.raw_input()
    local -- passed to InteractiveInterpreter.__init__()
    exitmsg -- passed to InteractiveConsole.interact()
    """
    console = InteractiveConsole(local)
    if readfunc is not None:
        console.raw_input = readfunc
    else:
        try:
            import readline
        except ImportError:
            pass
    console.interact(banner, exitmsg)
 if __name__ == "__main__":
    import argparse
    parser = argparse.ArgumentParser()
    parser.add_argument('-q', action='store_true',
                       help="don't print version and copyright messages")
    args = parser.parse_args()
    if args.q or sys.flags.quiet:
        banner = ''
    else:
        banner = None
    interact(banner)
--- a/Show more
+++ b/Show more
		`@ -0,0 +1 @@`
							`# This file exists as a helper for the test.test_frozen module.`