html5lib
========
.. image:: https://travis-ci.org/html5lib/html5lib-python.png?branch=master
:target: https://travis-ci.org/html5lib/html5lib-python
html5lib is a pure-python library for parsing HTML. It is designed to
conform to the WHATWG HTML specification, as is implemented by all major
web browsers.
Usage
-----
Simple usage follows this pattern:
.. code-block:: python
import html5lib
with open("mydocument.html", "rb") as f:
document = html5lib.parse(f)
or:
.. code-block:: python
import html5lib
document = html5lib.parse("
Hello World!")
By default, the ``document`` will be an ``xml.etree`` element instance.
Whenever possible, html5lib chooses the accelerated ``ElementTree``
implementation (i.e. ``xml.etree.cElementTree`` on Python 2.x).
Two other tree types are supported: ``xml.dom.minidom`` and
``lxml.etree``. To use an alternative format, specify the name of
a treebuilder:
.. code-block:: python
import html5lib
with open("mydocument.html", "rb") as f:
lxml_etree_document = html5lib.parse(f, treebuilder="lxml")
When using with ``urllib2`` (Python 2), the charset from HTTP should be
pass into html5lib as follows:
.. code-block:: python
from contextlib import closing
from urllib2 import urlopen
import html5lib
with closing(urlopen("http://example.com/")) as f:
document = html5lib.parse(f, encoding=f.info().getparam("charset"))
When using with ``urllib.request`` (Python 3), the charset from HTTP
should be pass into html5lib as follows:
.. code-block:: python
from urllib.request import urlopen
import html5lib
with urlopen("http://example.com/") as f:
document = html5lib.parse(f, encoding=f.info().get_content_charset())
To have more control over the parser, create a parser object explicitly.
For instance, to make the parser raise exceptions on parse errors, use:
.. code-block:: python
import html5lib
with open("mydocument.html", "rb") as f:
parser = html5lib.HTMLParser(strict=True)
document = parser.parse(f)
When you're instantiating parser objects explicitly, pass a treebuilder
class as the ``tree`` keyword argument to use an alternative document
format:
.. code-block:: python
import html5lib
parser = html5lib.HTMLParser(tree=html5lib.getTreeBuilder("dom"))
minidom_document = parser.parse("
Hello World!")
More documentation is available at http://html5lib.readthedocs.org/.
Installation
------------
html5lib works on CPython 2.6+, CPython 3.2+ and PyPy. To install it,
use:
.. code-block:: bash
$ pip install html5lib
Optional Dependencies
---------------------
The following third-party libraries may be used for additional
functionality:
- ``datrie`` can be used to improve parsing performance (though in
almost all cases the improvement is marginal);
- ``lxml`` is supported as a tree format (for both building and
walking) under CPython (but *not* PyPy where it is known to cause
segfaults);
- ``genshi`` has a treewalker (but not builder); and
- ``charade`` can be used as a fallback when character encoding cannot
be determined; ``chardet``, from which it was forked, can also be used
on Python 2.
- ``ordereddict`` can be used under Python 2.6
(``collections.OrderedDict`` is used instead on later versions) to
serialize attributes in alphabetical order.
Bugs
----
Please report any bugs on the `issue tracker
`_.
Tests
-----
Unit tests require the ``nose`` library and can be run using the
``nosetests`` command in the root directory; ``ordereddict`` is
required under Python 2.6. All should pass.
Test data are contained in a separate `html5lib-tests
`_ repository and included
as a submodule, thus for git checkouts they must be initialized::
$ git submodule init
$ git submodule update
If you have all compatible Python implementations available on your
system, you can run tests on all of them using the ``tox`` utility,
which can be found on PyPI.
Questions?
----------
There's a mailing list available for support on Google Groups,
`html5lib-discuss `_,
though you may get a quicker response asking on IRC in `#whatwg on
irc.freenode.net `_.
Change Log
----------
0.9999999/1.0b8
~~~~~~~~~~~~~~~
Released on September 10, 2015
* Fix #195: fix the sanitizer to drop broken URLs (it threw an
exception between 0.9999 and 0.999999).
0.999999/1.0b7
~~~~~~~~~~~~~~
Released on July 7, 2015
* Fix #189: fix the sanitizer to allow relative URLs again (as it did
prior to 0.9999/1.0b5).
0.99999/1.0b6
~~~~~~~~~~~~~
Released on April 30, 2015
* Fix #188: fix the sanitizer to not throw an exception when sanitizing
bogus data URLs.
0.9999/1.0b5
~~~~~~~~~~~~
Released on April 29, 2015
* Fix #153: Sanitizer fails to treat some attributes as URLs. Despite how
this sounds, this has no known security implications. No known version
of IE (5.5 to current), Firefox (3 to current), Safari (6 to current),
Chrome (1 to current), or Opera (12 to current) will run any script
provided in these attributes.
* Pass error message to the ParseError exception in strict parsing mode.
* Allow data URIs in the sanitizer, with a whitelist of content-types.
* Add support for Python implementations that don't support lone
surrogates (read: Jython). Fixes #2.
* Remove localization of error messages. This functionality was totally
unused (and untested that everything was localizable), so we may as
well follow numerous browsers in not supporting translating technical
strings.
* Expose treewalkers.pprint as a public API.
* Add a documentEncoding property to HTML5Parser, fix #121.
0.999
~~~~~
Released on December 23, 2013
* Fix #127: add work-around for CPython issue #20007: .read(0) on
http.client.HTTPResponse drops the rest of the content.
* Fix #115: lxml treewalker can now deal with fragments containing, at
their root level, text nodes with non-ASCII characters on Python 2.
0.99
~~~~
Released on September 10, 2013
* No library changes from 1.0b3; released as 0.99 as pip has changed
behaviour from 1.4 to avoid installing pre-release versions per
PEP 440.
1.0b3
~~~~~
Released on July 24, 2013
* Removed ``RecursiveTreeWalker`` from ``treewalkers._base``. Any
implementation using it should be moved to
``NonRecursiveTreeWalker``, as everything bundled with html5lib has
for years.
* Fix #67 so that ``BufferedStream`` to correctly returns a bytes
object, thereby fixing any case where html5lib is passed a
non-seekable RawIOBase-like object.
1.0b2
~~~~~
Released on June 27, 2013
* Removed reordering of attributes within the serializer. There is now
an ``alphabetical_attributes`` option which preserves the previous
behaviour through a new filter. This allows attribute order to be
preserved through html5lib if the tree builder preserves order.
* Removed ``dom2sax`` from DOM treebuilders. It has been replaced by
``treeadapters.sax.to_sax`` which is generic and supports any
treewalker; it also resolves all known bugs with ``dom2sax``.
* Fix treewalker assertions on hitting bytes strings on
Python 2. Previous to 1.0b1, treewalkers coped with mixed
bytes/unicode data on Python 2; this reintroduces this prior
behaviour on Python 2. Behaviour is unchanged on Python 3.
1.0b1
~~~~~
Released on May 17, 2013
* Implementation updated to implement the `HTML specification
`_ as of 5th May
2013 (`SVN `_ revision r7867).
* Python 3.2+ supported in a single codebase using the ``six`` library.
* Removed support for Python 2.5 and older.
* Removed the deprecated Beautiful Soup 3 treebuilder.
``beautifulsoup4`` can use ``html5lib`` as a parser instead. Note that
since it doesn't support namespaces, foreign content like SVG and
MathML is parsed incorrectly.
* Removed ``simpletree`` from the package. The default tree builder is
now ``etree`` (using the ``xml.etree.cElementTree`` implementation if
available, and ``xml.etree.ElementTree`` otherwise).
* Removed the ``XHTMLSerializer`` as it never actually guaranteed its
output was well-formed XML, and hence provided little of use.
* Removed default DOM treebuilder, so ``html5lib.treebuilders.dom`` is no
longer supported. ``html5lib.treebuilders.getTreeBuilder("dom")`` will
return the default DOM treebuilder, which uses ``xml.dom.minidom``.
* Optional heuristic character encoding detection now based on
``charade`` for Python 2.6 - 3.3 compatibility.
* Optional ``Genshi`` treewalker support fixed.
* Many bugfixes, including:
* #33: null in attribute value breaks XML AttValue;
* #4: nested, indirect descendant,