Source code for json

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:`json` exposes an API familiar to users of the standard library
:mod:`marshal` and :mod:`pickle` modules.  It is derived from a
version of the externally maintained simplejson library.

Encoding basic Python object hierarchies::

    >>> import 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('\u1234'))
    "\u1234"
    >>> print(json.dumps('\\'))
    "\\"
    >>> print(json.dumps({"c": 0, "b": 0, "a": 0}, sort_keys=True))
    {"a": 0, "b": 0, "c": 0}
    >>> from io import StringIO
    >>> io = StringIO()
    >>> json.dump(['streaming API'], io)
    >>> io.getvalue()
    '["streaming API"]'

Compact encoding::

    >>> import json
    >>> from collections import OrderedDict
    >>> mydict = OrderedDict([('4', 5), ('6', 7)])
    >>> json.dumps([1,2,3,mydict], separators=(',', ':'))
    '[1,2,3,{"4":5,"6":7}]'

Pretty printing::

    >>> import json
    >>> print(json.dumps({'4': 5, '6': 7}, sort_keys=True, indent=4))
    {
        "4": 5,
        "6": 7
    }

Decoding JSON::

    >>> import json
    >>> obj = ['foo', {'bar': ['baz', None, 1.0, 2]}]
    >>> json.loads('["foo", {"bar":["baz", null, 1.0, 2]}]') == obj
    True
    >>> json.loads('"\\"foo\\bar"') == '"foo\x08ar'
    True
    >>> from io import StringIO
    >>> io = StringIO('["streaming API"]')
    >>> json.load(io)[0] == 'streaming API'
    True

Specializing JSON object decoding::

    >>> import 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 json
    >>> def encode_complex(obj):
    ...     if isinstance(obj, complex):
    ...         return [obj.real, obj.imag]
    ...     raise TypeError(repr(o) + " is not JSON serializable")
    ...
    >>> 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 json.tool from the shell to validate and pretty-print::

    $ echo '{"json":"obj"}' | python -m json.tool
    {
        "json": "obj"
    }
    $ echo '{ 1.2:3.4}' | python -m json.tool
    Expecting property name enclosed in double quotes: line 1 column 3 (char 2)
"""
__version__ = '2.0.9'
__all__ = [
    'dump', 'dumps', 'load', 'loads',
    'JSONDecoder', 'JSONEncoder',
]

__author__ = 'Bob Ippolito <bob@redivi.com>'

from .decoder import JSONDecoder
from .encoder import JSONEncoder

_default_encoder = JSONEncoder(
    skipkeys=False,
    ensure_ascii=True,
    check_circular=True,
    allow_nan=True,
    indent=None,
    separators=None,
    default=None,
)

[docs]def dump(obj, fp, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, cls=None, indent=None, separators=None, default=None, sort_keys=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``, ``int``, ``float``, ``bool``, ``None``) will be skipped instead of raising a ``TypeError``. If ``ensure_ascii`` is false, then the strings written to ``fp`` can contain non-ASCII characters if they appear in strings contained in ``obj``. Otherwise, all such characters are escaped in JSON strings. 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 non-negative integer, then JSON array elements and object members will be pretty-printed with that indent level. An indent level of 0 will only insert newlines. ``None`` is the most compact representation. 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. ``default(obj)`` is a function that should return a serializable version of obj or raise TypeError. The default simply raises TypeError. If *sort_keys* is ``True`` (default: ``False``), then the output of dictionaries will be sorted by key. To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the ``.default()`` method to serialize additional types), specify it with the ``cls`` kwarg; otherwise ``JSONEncoder`` is used. """ # 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 default is None and not sort_keys 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, default=default, sort_keys=sort_keys, **kw).iterencode(obj) # could accelerate with writelines in some versions of Python, at # a debuggability cost for chunk in iterable: fp.write(chunk)
[docs]def dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, cls=None, indent=None, separators=None, default=None, sort_keys=False, **kw): """Serialize ``obj`` to a JSON formatted ``str``. If ``skipkeys`` is false then ``dict`` keys that are not basic types (``str``, ``int``, ``float``, ``bool``, ``None``) will be skipped instead of raising a ``TypeError``. If ``ensure_ascii`` is false, then the return value can contain non-ASCII characters if they appear in strings contained in ``obj``. Otherwise, all such characters are escaped in JSON strings. 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 non-negative integer, then JSON array elements and object members will be pretty-printed with that indent level. An indent level of 0 will only insert newlines. ``None`` is the most compact representation. 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. ``default(obj)`` is a function that should return a serializable version of obj or raise TypeError. The default simply raises TypeError. If *sort_keys* is ``True`` (default: ``False``), then the output of dictionaries will be sorted by key. To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the ``.default()`` method to serialize additional types), specify it with the ``cls`` kwarg; otherwise ``JSONEncoder`` is used. """ # 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 default is None and not sort_keys 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, default=default, sort_keys=sort_keys, **kw).encode(obj)
_default_decoder = JSONDecoder(object_hook=None, object_pairs_hook=None)
[docs]def load(fp, cls=None, object_hook=None, parse_float=None, parse_int=None, parse_constant=None, object_pairs_hook=None, **kw): """Deserialize ``fp`` (a ``.read()``-supporting file-like object containing a JSON document) to a Python object. ``object_hook`` is an optional function that will be called with the result of any object literal decode (a ``dict``). The return value of ``object_hook`` will be used instead of the ``dict``. This feature can be used to implement custom decoders (e.g. JSON-RPC class hinting). ``object_pairs_hook`` is an optional function that will be called with the result of any object literal decoded with an ordered list of pairs. The return value of ``object_pairs_hook`` will be used instead of the ``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, collections.OrderedDict will remember the order of insertion). If ``object_hook`` is also defined, the ``object_pairs_hook`` takes priority. To use a custom ``JSONDecoder`` subclass, specify it with the ``cls`` kwarg; otherwise ``JSONDecoder`` is used. """ return loads(fp.read(), cls=cls, object_hook=object_hook, parse_float=parse_float, parse_int=parse_int, parse_constant=parse_constant, object_pairs_hook=object_pairs_hook, **kw)
[docs]def loads(s, encoding=None, cls=None, object_hook=None, parse_float=None, parse_int=None, parse_constant=None, object_pairs_hook=None, **kw): """Deserialize ``s`` (a ``str`` instance containing a JSON document) to a Python object. ``object_hook`` is an optional function that will be called with the result of any object literal decode (a ``dict``). The return value of ``object_hook`` will be used instead of the ``dict``. This feature can be used to implement custom decoders (e.g. JSON-RPC class hinting). ``object_pairs_hook`` is an optional function that will be called with the result of any object literal decoded with an ordered list of pairs. The return value of ``object_pairs_hook`` will be used instead of the ``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, 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. 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. float). ``parse_constant``, if specified, will be called with one of the following strings: -Infinity, Infinity, NaN, null, true, false. This can be used to raise an exception if invalid JSON numbers are encountered. To use a custom ``JSONDecoder`` subclass, specify it with the ``cls`` kwarg; otherwise ``JSONDecoder`` is used. The ``encoding`` argument is ignored and deprecated. """ if not isinstance(s, str): raise TypeError('the JSON object must be str, not {!r}'.format( s.__class__.__name__)) if s.startswith(u'\ufeff'): raise ValueError("Unexpected UTF-8 BOM (decode using utf-8-sig)") if (cls 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 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 return cls(**kw).decode(s)