openmedialibrary_platform_w.../Lib/site-packages/simplejson/__init__.py

577 lines
23 KiB
Python

r"""JSON (JavaScript Object Notation) <http://json.org> is a subset of
JavaScript syntax (ECMA-262 3rd edition) used as a lightweight data
interchange format.
:mod:`simplejson` exposes an API familiar to users of the standard library
:mod:`marshal` and :mod:`pickle` modules. It is the externally maintained
version of the :mod:`json` library contained in Python 2.6, but maintains
compatibility back to Python 2.5 and (currently) has significant performance
advantages, even without using the optional C extension for speedups.
Encoding basic Python object hierarchies::
>>> import simplejson as json
>>> json.dumps(['foo', {'bar': ('baz', None, 1.0, 2)}])
'["foo", {"bar": ["baz", null, 1.0, 2]}]'
>>> print(json.dumps("\"foo\bar"))
"\"foo\bar"
>>> print(json.dumps(u'\u1234'))
"\u1234"
>>> print(json.dumps('\\'))
"\\"
>>> print(json.dumps({"c": 0, "b": 0, "a": 0}, sort_keys=True))
{"a": 0, "b": 0, "c": 0}
>>> from simplejson.compat import StringIO
>>> io = StringIO()
>>> json.dump(['streaming API'], io)
>>> io.getvalue()
'["streaming API"]'
Compact encoding::
>>> import simplejson as json
>>> obj = [1,2,3,{'4': 5, '6': 7}]
>>> json.dumps(obj, separators=(',',':'), sort_keys=True)
'[1,2,3,{"4":5,"6":7}]'
Pretty printing::
>>> import simplejson as json
>>> print(json.dumps({'4': 5, '6': 7}, sort_keys=True, indent=' '))
{
"4": 5,
"6": 7
}
Decoding JSON::
>>> import simplejson as json
>>> obj = [u'foo', {u'bar': [u'baz', None, 1.0, 2]}]
>>> json.loads('["foo", {"bar":["baz", null, 1.0, 2]}]') == obj
True
>>> json.loads('"\\"foo\\bar"') == u'"foo\x08ar'
True
>>> from simplejson.compat import StringIO
>>> io = StringIO('["streaming API"]')
>>> json.load(io)[0] == 'streaming API'
True
Specializing JSON object decoding::
>>> import simplejson as json
>>> def as_complex(dct):
... if '__complex__' in dct:
... return complex(dct['real'], dct['imag'])
... return dct
...
>>> json.loads('{"__complex__": true, "real": 1, "imag": 2}',
... object_hook=as_complex)
(1+2j)
>>> from decimal import Decimal
>>> json.loads('1.1', parse_float=Decimal) == Decimal('1.1')
True
Specializing JSON object encoding::
>>> import simplejson as json
>>> def encode_complex(obj):
... if isinstance(obj, complex):
... return [obj.real, obj.imag]
... raise TypeError('Object of type %s is not JSON serializable' %
... obj.__class__.__name__)
...
>>> json.dumps(2 + 1j, default=encode_complex)
'[2.0, 1.0]'
>>> json.JSONEncoder(default=encode_complex).encode(2 + 1j)
'[2.0, 1.0]'
>>> ''.join(json.JSONEncoder(default=encode_complex).iterencode(2 + 1j))
'[2.0, 1.0]'
Using simplejson.tool from the shell to validate and pretty-print::
$ echo '{"json":"obj"}' | python -m simplejson.tool
{
"json": "obj"
}
$ echo '{ 1.2:3.4}' | python -m simplejson.tool
Expecting property name: line 1 column 3 (char 2)
"""
from __future__ import absolute_import
__version__ = '3.16.0'
__all__ = [
'dump', 'dumps', 'load', 'loads',
'JSONDecoder', 'JSONDecodeError', 'JSONEncoder',
'OrderedDict', 'simple_first', 'RawJSON'
]
__author__ = 'Bob Ippolito <bob@redivi.com>'
from decimal import Decimal
from .errors import JSONDecodeError
from .raw_json import RawJSON
from .decoder import JSONDecoder
from .encoder import JSONEncoder, JSONEncoderForHTML
def _import_OrderedDict():
import collections
try:
return collections.OrderedDict
except AttributeError:
from . import ordered_dict
return ordered_dict.OrderedDict
OrderedDict = _import_OrderedDict()
def _import_c_make_encoder():
try:
from ._speedups import make_encoder
return make_encoder
except ImportError:
return None
_default_encoder = JSONEncoder(
skipkeys=False,
ensure_ascii=True,
check_circular=True,
allow_nan=True,
indent=None,
separators=None,
encoding='utf-8',
default=None,
use_decimal=True,
namedtuple_as_object=True,
tuple_as_array=True,
iterable_as_array=False,
bigint_as_string=False,
item_sort_key=None,
for_json=False,
ignore_nan=False,
int_as_string_bitcount=None,
)
def dump(obj, fp, skipkeys=False, ensure_ascii=True, check_circular=True,
allow_nan=True, cls=None, indent=None, separators=None,
encoding='utf-8', default=None, use_decimal=True,
namedtuple_as_object=True, tuple_as_array=True,
bigint_as_string=False, sort_keys=False, item_sort_key=None,
for_json=False, ignore_nan=False, int_as_string_bitcount=None,
iterable_as_array=False, **kw):
"""Serialize ``obj`` as a JSON formatted stream to ``fp`` (a
``.write()``-supporting file-like object).
If *skipkeys* is true then ``dict`` keys that are not basic types
(``str``, ``unicode``, ``int``, ``long``, ``float``, ``bool``, ``None``)
will be skipped instead of raising a ``TypeError``.
If *ensure_ascii* is false, then the some chunks written to ``fp``
may be ``unicode`` instances, subject to normal Python ``str`` to
``unicode`` coercion rules. Unless ``fp.write()`` explicitly
understands ``unicode`` (as in ``codecs.getwriter()``) this is likely
to cause an error.
If *check_circular* is false, then the circular reference check
for container types will be skipped and a circular reference will
result in an ``OverflowError`` (or worse).
If *allow_nan* is false, then it will be a ``ValueError`` to
serialize out of range ``float`` values (``nan``, ``inf``, ``-inf``)
in strict compliance of the original JSON specification, instead of using
the JavaScript equivalents (``NaN``, ``Infinity``, ``-Infinity``). See
*ignore_nan* for ECMA-262 compliant behavior.
If *indent* is a string, then JSON array elements and object members
will be pretty-printed with a newline followed by that string repeated
for each level of nesting. ``None`` (the default) selects the most compact
representation without any newlines. For backwards compatibility with
versions of simplejson earlier than 2.1.0, an integer is also accepted
and is converted to a string with that many spaces.
If specified, *separators* should be an
``(item_separator, key_separator)`` tuple. The default is ``(', ', ': ')``
if *indent* is ``None`` and ``(',', ': ')`` otherwise. To get the most
compact JSON representation, you should specify ``(',', ':')`` to eliminate
whitespace.
*encoding* is the character encoding for str instances, default is UTF-8.
*default(obj)* is a function that should return a serializable version
of obj or raise ``TypeError``. The default simply raises ``TypeError``.
If *use_decimal* is true (default: ``True``) then decimal.Decimal
will be natively serialized to JSON with full precision.
If *namedtuple_as_object* is true (default: ``True``),
:class:`tuple` subclasses with ``_asdict()`` methods will be encoded
as JSON objects.
If *tuple_as_array* is true (default: ``True``),
:class:`tuple` (and subclasses) will be encoded as JSON arrays.
If *iterable_as_array* is true (default: ``False``),
any object not in the above table that implements ``__iter__()``
will be encoded as a JSON array.
If *bigint_as_string* is true (default: ``False``), ints 2**53 and higher
or lower than -2**53 will be encoded as strings. This is to avoid the
rounding that happens in Javascript otherwise. Note that this is still a
lossy operation that will not round-trip correctly and should be used
sparingly.
If *int_as_string_bitcount* is a positive number (n), then int of size
greater than or equal to 2**n or lower than or equal to -2**n will be
encoded as strings.
If specified, *item_sort_key* is a callable used to sort the items in
each dictionary. This is useful if you want to sort items other than
in alphabetical order by key. This option takes precedence over
*sort_keys*.
If *sort_keys* is true (default: ``False``), the output of dictionaries
will be sorted by item.
If *for_json* is true (default: ``False``), objects with a ``for_json()``
method will use the return value of that method for encoding as JSON
instead of the object.
If *ignore_nan* is true (default: ``False``), then out of range
:class:`float` values (``nan``, ``inf``, ``-inf``) will be serialized as
``null`` in compliance with the ECMA-262 specification. If true, this will
override *allow_nan*.
To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the
``.default()`` method to serialize additional types), specify it with
the ``cls`` kwarg. NOTE: You should use *default* or *for_json* instead
of subclassing whenever possible.
"""
# cached encoder
if (not skipkeys and ensure_ascii and
check_circular and allow_nan and
cls is None and indent is None and separators is None and
encoding == 'utf-8' and default is None and use_decimal
and namedtuple_as_object and tuple_as_array and not iterable_as_array
and not bigint_as_string and not sort_keys
and not item_sort_key and not for_json
and not ignore_nan and int_as_string_bitcount is None
and not kw
):
iterable = _default_encoder.iterencode(obj)
else:
if cls is None:
cls = JSONEncoder
iterable = cls(skipkeys=skipkeys, ensure_ascii=ensure_ascii,
check_circular=check_circular, allow_nan=allow_nan, indent=indent,
separators=separators, encoding=encoding,
default=default, use_decimal=use_decimal,
namedtuple_as_object=namedtuple_as_object,
tuple_as_array=tuple_as_array,
iterable_as_array=iterable_as_array,
bigint_as_string=bigint_as_string,
sort_keys=sort_keys,
item_sort_key=item_sort_key,
for_json=for_json,
ignore_nan=ignore_nan,
int_as_string_bitcount=int_as_string_bitcount,
**kw).iterencode(obj)
# could accelerate with writelines in some versions of Python, at
# a debuggability cost
for chunk in iterable:
fp.write(chunk)
def dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True,
allow_nan=True, cls=None, indent=None, separators=None,
encoding='utf-8', default=None, use_decimal=True,
namedtuple_as_object=True, tuple_as_array=True,
bigint_as_string=False, sort_keys=False, item_sort_key=None,
for_json=False, ignore_nan=False, int_as_string_bitcount=None,
iterable_as_array=False, **kw):
"""Serialize ``obj`` to a JSON formatted ``str``.
If ``skipkeys`` is false then ``dict`` keys that are not basic types
(``str``, ``unicode``, ``int``, ``long``, ``float``, ``bool``, ``None``)
will be skipped instead of raising a ``TypeError``.
If ``ensure_ascii`` is false, then the return value will be a
``unicode`` instance subject to normal Python ``str`` to ``unicode``
coercion rules instead of being escaped to an ASCII ``str``.
If ``check_circular`` is false, then the circular reference check
for container types will be skipped and a circular reference will
result in an ``OverflowError`` (or worse).
If ``allow_nan`` is false, then it will be a ``ValueError`` to
serialize out of range ``float`` values (``nan``, ``inf``, ``-inf``) in
strict compliance of the JSON specification, instead of using the
JavaScript equivalents (``NaN``, ``Infinity``, ``-Infinity``).
If ``indent`` is a string, then JSON array elements and object members
will be pretty-printed with a newline followed by that string repeated
for each level of nesting. ``None`` (the default) selects the most compact
representation without any newlines. For backwards compatibility with
versions of simplejson earlier than 2.1.0, an integer is also accepted
and is converted to a string with that many spaces.
If specified, ``separators`` should be an
``(item_separator, key_separator)`` tuple. The default is ``(', ', ': ')``
if *indent* is ``None`` and ``(',', ': ')`` otherwise. To get the most
compact JSON representation, you should specify ``(',', ':')`` to eliminate
whitespace.
``encoding`` is the character encoding for str instances, default is UTF-8.
``default(obj)`` is a function that should return a serializable version
of obj or raise TypeError. The default simply raises TypeError.
If *use_decimal* is true (default: ``True``) then decimal.Decimal
will be natively serialized to JSON with full precision.
If *namedtuple_as_object* is true (default: ``True``),
:class:`tuple` subclasses with ``_asdict()`` methods will be encoded
as JSON objects.
If *tuple_as_array* is true (default: ``True``),
:class:`tuple` (and subclasses) will be encoded as JSON arrays.
If *iterable_as_array* is true (default: ``False``),
any object not in the above table that implements ``__iter__()``
will be encoded as a JSON array.
If *bigint_as_string* is true (not the default), ints 2**53 and higher
or lower than -2**53 will be encoded as strings. This is to avoid the
rounding that happens in Javascript otherwise.
If *int_as_string_bitcount* is a positive number (n), then int of size
greater than or equal to 2**n or lower than or equal to -2**n will be
encoded as strings.
If specified, *item_sort_key* is a callable used to sort the items in
each dictionary. This is useful if you want to sort items other than
in alphabetical order by key. This option takes precendence over
*sort_keys*.
If *sort_keys* is true (default: ``False``), the output of dictionaries
will be sorted by item.
If *for_json* is true (default: ``False``), objects with a ``for_json()``
method will use the return value of that method for encoding as JSON
instead of the object.
If *ignore_nan* is true (default: ``False``), then out of range
:class:`float` values (``nan``, ``inf``, ``-inf``) will be serialized as
``null`` in compliance with the ECMA-262 specification. If true, this will
override *allow_nan*.
To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the
``.default()`` method to serialize additional types), specify it with
the ``cls`` kwarg. NOTE: You should use *default* instead of subclassing
whenever possible.
"""
# cached encoder
if (not skipkeys and ensure_ascii and
check_circular and allow_nan and
cls is None and indent is None and separators is None and
encoding == 'utf-8' and default is None and use_decimal
and namedtuple_as_object and tuple_as_array and not iterable_as_array
and not bigint_as_string and not sort_keys
and not item_sort_key and not for_json
and not ignore_nan and int_as_string_bitcount is None
and not kw
):
return _default_encoder.encode(obj)
if cls is None:
cls = JSONEncoder
return cls(
skipkeys=skipkeys, ensure_ascii=ensure_ascii,
check_circular=check_circular, allow_nan=allow_nan, indent=indent,
separators=separators, encoding=encoding, default=default,
use_decimal=use_decimal,
namedtuple_as_object=namedtuple_as_object,
tuple_as_array=tuple_as_array,
iterable_as_array=iterable_as_array,
bigint_as_string=bigint_as_string,
sort_keys=sort_keys,
item_sort_key=item_sort_key,
for_json=for_json,
ignore_nan=ignore_nan,
int_as_string_bitcount=int_as_string_bitcount,
**kw).encode(obj)
_default_decoder = JSONDecoder(encoding=None, object_hook=None,
object_pairs_hook=None)
def load(fp, encoding=None, cls=None, object_hook=None, parse_float=None,
parse_int=None, parse_constant=None, object_pairs_hook=None,
use_decimal=False, namedtuple_as_object=True, tuple_as_array=True,
**kw):
"""Deserialize ``fp`` (a ``.read()``-supporting file-like object containing
a JSON document) to a Python object.
*encoding* determines the encoding used to interpret any
:class:`str` objects decoded by this instance (``'utf-8'`` by
default). It has no effect when decoding :class:`unicode` objects.
Note that currently only encodings that are a superset of ASCII work,
strings of other encodings should be passed in as :class:`unicode`.
*object_hook*, if specified, will be called with the result of every
JSON object decoded and its return value will be used in place of the
given :class:`dict`. This can be used to provide custom
deserializations (e.g. to support JSON-RPC class hinting).
*object_pairs_hook* is an optional function that will be called with
the result of any object literal decode with an ordered list of pairs.
The return value of *object_pairs_hook* will be used instead of the
:class:`dict`. This feature can be used to implement custom decoders
that rely on the order that the key and value pairs are decoded (for
example, :func:`collections.OrderedDict` will remember the order of
insertion). If *object_hook* is also defined, the *object_pairs_hook*
takes priority.
*parse_float*, if specified, will be called with the string of every
JSON float to be decoded. By default, this is equivalent to
``float(num_str)``. This can be used to use another datatype or parser
for JSON floats (e.g. :class:`decimal.Decimal`).
*parse_int*, if specified, will be called with the string of every
JSON int to be decoded. By default, this is equivalent to
``int(num_str)``. This can be used to use another datatype or parser
for JSON integers (e.g. :class:`float`).
*parse_constant*, if specified, will be called with one of the
following strings: ``'-Infinity'``, ``'Infinity'``, ``'NaN'``. This
can be used to raise an exception if invalid JSON numbers are
encountered.
If *use_decimal* is true (default: ``False``) then it implies
parse_float=decimal.Decimal for parity with ``dump``.
To use a custom ``JSONDecoder`` subclass, specify it with the ``cls``
kwarg. NOTE: You should use *object_hook* or *object_pairs_hook* instead
of subclassing whenever possible.
"""
return loads(fp.read(),
encoding=encoding, cls=cls, object_hook=object_hook,
parse_float=parse_float, parse_int=parse_int,
parse_constant=parse_constant, object_pairs_hook=object_pairs_hook,
use_decimal=use_decimal, **kw)
def loads(s, encoding=None, cls=None, object_hook=None, parse_float=None,
parse_int=None, parse_constant=None, object_pairs_hook=None,
use_decimal=False, **kw):
"""Deserialize ``s`` (a ``str`` or ``unicode`` instance containing a JSON
document) to a Python object.
*encoding* determines the encoding used to interpret any
:class:`str` objects decoded by this instance (``'utf-8'`` by
default). It has no effect when decoding :class:`unicode` objects.
Note that currently only encodings that are a superset of ASCII work,
strings of other encodings should be passed in as :class:`unicode`.
*object_hook*, if specified, will be called with the result of every
JSON object decoded and its return value will be used in place of the
given :class:`dict`. This can be used to provide custom
deserializations (e.g. to support JSON-RPC class hinting).
*object_pairs_hook* is an optional function that will be called with
the result of any object literal decode with an ordered list of pairs.
The return value of *object_pairs_hook* will be used instead of the
:class:`dict`. This feature can be used to implement custom decoders
that rely on the order that the key and value pairs are decoded (for
example, :func:`collections.OrderedDict` will remember the order of
insertion). If *object_hook* is also defined, the *object_pairs_hook*
takes priority.
*parse_float*, if specified, will be called with the string of every
JSON float to be decoded. By default, this is equivalent to
``float(num_str)``. This can be used to use another datatype or parser
for JSON floats (e.g. :class:`decimal.Decimal`).
*parse_int*, if specified, will be called with the string of every
JSON int to be decoded. By default, this is equivalent to
``int(num_str)``. This can be used to use another datatype or parser
for JSON integers (e.g. :class:`float`).
*parse_constant*, if specified, will be called with one of the
following strings: ``'-Infinity'``, ``'Infinity'``, ``'NaN'``. This
can be used to raise an exception if invalid JSON numbers are
encountered.
If *use_decimal* is true (default: ``False``) then it implies
parse_float=decimal.Decimal for parity with ``dump``.
To use a custom ``JSONDecoder`` subclass, specify it with the ``cls``
kwarg. NOTE: You should use *object_hook* or *object_pairs_hook* instead
of subclassing whenever possible.
"""
if (cls is None and encoding is None and object_hook is None and
parse_int is None and parse_float is None and
parse_constant is None and object_pairs_hook is None
and not use_decimal and not kw):
return _default_decoder.decode(s)
if cls is None:
cls = JSONDecoder
if object_hook is not None:
kw['object_hook'] = object_hook
if object_pairs_hook is not None:
kw['object_pairs_hook'] = object_pairs_hook
if parse_float is not None:
kw['parse_float'] = parse_float
if parse_int is not None:
kw['parse_int'] = parse_int
if parse_constant is not None:
kw['parse_constant'] = parse_constant
if use_decimal:
if parse_float is not None:
raise TypeError("use_decimal=True implies parse_float=Decimal")
kw['parse_float'] = Decimal
return cls(encoding=encoding, **kw).decode(s)
def _toggle_speedups(enabled):
from . import decoder as dec
from . import encoder as enc
from . import scanner as scan
c_make_encoder = _import_c_make_encoder()
if enabled:
dec.scanstring = dec.c_scanstring or dec.py_scanstring
enc.c_make_encoder = c_make_encoder
enc.encode_basestring_ascii = (enc.c_encode_basestring_ascii or
enc.py_encode_basestring_ascii)
scan.make_scanner = scan.c_make_scanner or scan.py_make_scanner
else:
dec.scanstring = dec.py_scanstring
enc.c_make_encoder = None
enc.encode_basestring_ascii = enc.py_encode_basestring_ascii
scan.make_scanner = scan.py_make_scanner
dec.make_scanner = scan.make_scanner
global _default_decoder
_default_decoder = JSONDecoder(
encoding=None,
object_hook=None,
object_pairs_hook=None,
)
global _default_encoder
_default_encoder = JSONEncoder(
skipkeys=False,
ensure_ascii=True,
check_circular=True,
allow_nan=True,
indent=None,
separators=None,
encoding='utf-8',
default=None,
)
def simple_first(kv):
"""Helper function to pass to item_sort_key to sort simple
elements to the top, then container elements.
"""
return (isinstance(kv[1], (list, dict, tuple)), kv[0])