1 r"""JSON (JavaScript Object Notation) <http://json.org> is a subset of

     2 JavaScript syntax (ECMA-262 3rd edition) used as a lightweight data

     3 interchange format.

     4 

     5 :mod:`simplejson` exposes an API familiar to users of the standard library

     6 :mod:`marshal` and :mod:`pickle` modules. It is the externally maintained

     7 version of the :mod:`json` library contained in Python 2.6, but maintains

     8 compatibility with Python 2.4 and Python 2.5 and (currently) has

     9 significant performance advantages, even without using the optional C

    10 extension for speedups.

    11 

    12 Encoding basic Python object hierarchies::

    13 

    14     >>> import simplejson as json

    15     >>> json.dumps(['foo', {'bar': ('baz', None, 1.0, 2)}])

    16     '["foo", {"bar": ["baz", null, 1.0, 2]}]'

    17     >>> print json.dumps("\"foo\bar")

    18     "\"foo\bar"

    19     >>> print json.dumps(u'\u1234')

    20     "\u1234"

    21     >>> print json.dumps('\\')

    22     "\\"

    23     >>> print json.dumps({"c": 0, "b": 0, "a": 0}, sort_keys=True)

    24     {"a": 0, "b": 0, "c": 0}

    25     >>> from StringIO import StringIO

    26     >>> io = StringIO()

    27     >>> json.dump(['streaming API'], io)

    28     >>> io.getvalue()

    29     '["streaming API"]'

    30 

    31 Compact encoding::

    32 

    33     >>> import simplejson as json

    34     >>> json.dumps([1,2,3,{'4': 5, '6': 7}], separators=(',',':'))

    35     '[1,2,3,{"4":5,"6":7}]'

    36 

    37 Pretty printing::

    38 

    39     >>> import simplejson as json

    40     >>> s = json.dumps({'4': 5, '6': 7}, sort_keys=True, indent=4)

    41     >>> print '\n'.join([l.rstrip() for l in  s.splitlines()])

    42     {

    43         "4": 5,

    44         "6": 7

    45     }

    46 

    47 Decoding JSON::

    48 

    49     >>> import simplejson as json

    50     >>> obj = [u'foo', {u'bar': [u'baz', None, 1.0, 2]}]

    51     >>> json.loads('["foo", {"bar":["baz", null, 1.0, 2]}]') == obj

    52     True

    53     >>> json.loads('"\\"foo\\bar"') == u'"foo\x08ar'

    54     True

    55     >>> from StringIO import StringIO

    56     >>> io = StringIO('["streaming API"]')

    57     >>> json.load(io)[0] == 'streaming API'

    58     True

    59 

    60 Specializing JSON object decoding::

    61 

    62     >>> import simplejson as json

    63     >>> def as_complex(dct):

    64     ...     if '__complex__' in dct:

    65     ...         return complex(dct['real'], dct['imag'])

    66     ...     return dct

    67     ...

    68     >>> json.loads('{"__complex__": true, "real": 1, "imag": 2}',

    69     ...     object_hook=as_complex)

    70     (1+2j)

    71     >>> import decimal

    72     >>> json.loads('1.1', parse_float=decimal.Decimal) == decimal.Decimal('1.1')

    73     True

    74 

    75 Specializing JSON object encoding::

    76 

    77     >>> import simplejson as json

    78     >>> def encode_complex(obj):

    79     ...     if isinstance(obj, complex):

    80     ...         return [obj.real, obj.imag]

    81     ...     raise TypeError("%r is not JSON serializable" % (o,))

    82     ...

    83     >>> json.dumps(2 + 1j, default=encode_complex)

    84     '[2.0, 1.0]'

    85     >>> json.JSONEncoder(default=encode_complex).encode(2 + 1j)

    86     '[2.0, 1.0]'

    87     >>> ''.join(json.JSONEncoder(default=encode_complex).iterencode(2 + 1j))

    88     '[2.0, 1.0]'

    89 

    90 

    91 Using simplejson.tool from the shell to validate and pretty-print::

    92 

    93     $ echo '{"json":"obj"}' | python -msimplejson.tool

    94     {

    95         "json": "obj"

    96     }

    97     $ echo '{ 1.2:3.4}' | python -msimplejson.tool

    98     Expecting property name: line 1 column 2 (char 2)

    99 """

   100 

   101 # Django modification: try to use the system version first, providing it's

   102 # either of a later version of has the C speedups in place. Otherwise, fall

   103 # back to our local copy.

   104 

   105 __version__ = '2.0.7'

   106 

   107 use_system_version = False

   108 try:

   109     # The system-installed version has priority providing it is either not an

   110     # earlier version or it contains the C speedups.

   111     import simplejson

   112     if (simplejson.__version__.split('.') >= __version__.split('.') or

   113             hasattr(simplejson, '_speedups')):

   114         from simplejson import *

   115         use_system_version = True

   116 except ImportError:

   117     pass

   118 

   119 if not use_system_version:

   120     try:

   121         from json import *      # Python 2.6 preferred over local copy.

   122 

   123         # There is a "json" package around that is not Python's "json", so we

   124         # check for something that is only in the namespace of the version we

   125         # want.

   126         JSONDecoder

   127 

   128         use_system_version = True

   129     except (ImportError, NameError):

   130         pass

   131 

   132 # If all else fails, we have a bundled version that can be used.

   133 if not use_system_version:

   134     __all__ = [

   135         'dump', 'dumps', 'load', 'loads',

   136         'JSONDecoder', 'JSONEncoder',

   137     ]

   138 

   139     from django.utils.simplejson.decoder import JSONDecoder

   140     from django.utils.simplejson.encoder import JSONEncoder

   141 

   142     _default_encoder = JSONEncoder(

   143         skipkeys=False,

   144         ensure_ascii=True,

   145         check_circular=True,

   146         allow_nan=True,

   147         indent=None,

   148         separators=None,

   149         encoding='utf-8',

   150         default=None,

   151     )

   152 

   153     def dump(obj, fp, skipkeys=False, ensure_ascii=True, check_circular=True,

   154             allow_nan=True, cls=None, indent=None, separators=None,

   155             encoding='utf-8', default=None, **kw):

   156         """Serialize ``obj`` as a JSON formatted stream to ``fp`` (a

   157         ``.write()``-supporting file-like object).

   158 

   159         If ``skipkeys`` is ``True`` then ``dict`` keys that are not basic types

   160         (``str``, ``unicode``, ``int``, ``long``, ``float``, ``bool``, ``None``)

   161         will be skipped instead of raising a ``TypeError``.

   162 

   163         If ``ensure_ascii`` is ``False``, then the some chunks written to ``fp``

   164         may be ``unicode`` instances, subject to normal Python ``str`` to

   165         ``unicode`` coercion rules. Unless ``fp.write()`` explicitly

   166         understands ``unicode`` (as in ``codecs.getwriter()``) this is likely

   167         to cause an error.

   168 

   169         If ``check_circular`` is ``False``, then the circular reference check

   170         for container types will be skipped and a circular reference will

   171         result in an ``OverflowError`` (or worse).

   172 

   173         If ``allow_nan`` is ``False``, then it will be a ``ValueError`` to

   174         serialize out of range ``float`` values (``nan``, ``inf``, ``-inf``)

   175         in strict compliance of the JSON specification, instead of using the

   176         JavaScript equivalents (``NaN``, ``Infinity``, ``-Infinity``).

   177 

   178         If ``indent`` is a non-negative integer, then JSON array elements and object

   179         members will be pretty-printed with that indent level. An indent level

   180         of 0 will only insert newlines. ``None`` is the most compact representation.

   181 

   182         If ``separators`` is an ``(item_separator, dict_separator)`` tuple

   183         then it will be used instead of the default ``(', ', ': ')`` separators.

   184         ``(',', ':')`` is the most compact JSON representation.

   185 

   186         ``encoding`` is the character encoding for str instances, default is UTF-8.

   187 

   188         ``default(obj)`` is a function that should return a serializable version

   189         of obj or raise TypeError. The default simply raises TypeError.

   190 

   191         To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the

   192         ``.default()`` method to serialize additional types), specify it with

   193         the ``cls`` kwarg.

   194 

   195         """

   196         # cached encoder

   197         if (skipkeys is False and ensure_ascii is True and

   198             check_circular is True and allow_nan is True and

   199             cls is None and indent is None and separators is None and

   200             encoding == 'utf-8' and default is None and not kw):

   201             iterable = _default_encoder.iterencode(obj)

   202         else:

   203             if cls is None:

   204                 cls = JSONEncoder

   205             iterable = cls(skipkeys=skipkeys, ensure_ascii=ensure_ascii,

   206                 check_circular=check_circular, allow_nan=allow_nan, indent=indent,

   207                 separators=separators, encoding=encoding,

   208                 default=default, **kw).iterencode(obj)

   209         # could accelerate with writelines in some versions of Python, at

   210         # a debuggability cost

   211         for chunk in iterable:

   212             fp.write(chunk)

   213 

   214 

   215     def dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True,

   216             allow_nan=True, cls=None, indent=None, separators=None,

   217             encoding='utf-8', default=None, **kw):

   218         """Serialize ``obj`` to a JSON formatted ``str``.

   219 

   220         If ``skipkeys`` is ``True`` then ``dict`` keys that are not basic types

   221         (``str``, ``unicode``, ``int``, ``long``, ``float``, ``bool``, ``None``)

   222         will be skipped instead of raising a ``TypeError``.

   223 

   224         If ``ensure_ascii`` is ``False``, then the return value will be a

   225         ``unicode`` instance subject to normal Python ``str`` to ``unicode``

   226         coercion rules instead of being escaped to an ASCII ``str``.

   227 

   228         If ``check_circular`` is ``False``, then the circular reference check

   229         for container types will be skipped and a circular reference will

   230         result in an ``OverflowError`` (or worse).

   231 

   232         If ``allow_nan`` is ``False``, then it will be a ``ValueError`` to

   233         serialize out of range ``float`` values (``nan``, ``inf``, ``-inf``) in

   234         strict compliance of the JSON specification, instead of using the

   235         JavaScript equivalents (``NaN``, ``Infinity``, ``-Infinity``).

   236 

   237         If ``indent`` is a non-negative integer, then JSON array elements and

   238         object members will be pretty-printed with that indent level. An indent

   239         level of 0 will only insert newlines. ``None`` is the most compact

   240         representation.

   241 

   242         If ``separators`` is an ``(item_separator, dict_separator)`` tuple

   243         then it will be used instead of the default ``(', ', ': ')`` separators.

   244         ``(',', ':')`` is the most compact JSON representation.

   245 

   246         ``encoding`` is the character encoding for str instances, default is UTF-8.

   247 

   248         ``default(obj)`` is a function that should return a serializable version

   249         of obj or raise TypeError. The default simply raises TypeError.

   250 

   251         To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the

   252         ``.default()`` method to serialize additional types), specify it with

   253         the ``cls`` kwarg.

   254 

   255         """

   256         # cached encoder

   257         if (skipkeys is False and ensure_ascii is True and

   258             check_circular is True and allow_nan is True and

   259             cls is None and indent is None and separators is None and

   260             encoding == 'utf-8' and default is None and not kw):

   261             return _default_encoder.encode(obj)

   262         if cls is None:

   263             cls = JSONEncoder

   264         return cls(

   265             skipkeys=skipkeys, ensure_ascii=ensure_ascii,

   266             check_circular=check_circular, allow_nan=allow_nan, indent=indent,

   267             separators=separators, encoding=encoding, default=default,

   268             **kw).encode(obj)

   269 

   270 

   271     _default_decoder = JSONDecoder(encoding=None, object_hook=None)

   272 

   273 

   274     def load(fp, encoding=None, cls=None, object_hook=None, parse_float=None,

   275             parse_int=None, parse_constant=None, **kw):

   276         """Deserialize ``fp`` (a ``.read()``-supporting file-like object containing

   277         a JSON document) to a Python object.

   278 

   279         If the contents of ``fp`` is encoded with an ASCII based encoding other

   280         than utf-8 (e.g. latin-1), then an appropriate ``encoding`` name must

   281         be specified. Encodings that are not ASCII based (such as UCS-2) are

   282         not allowed, and should be wrapped with

   283         ``codecs.getreader(fp)(encoding)``, or simply decoded to a ``unicode``

   284         object and passed to ``loads()``

   285 

   286         ``object_hook`` is an optional function that will be called with the

   287         result of any object literal decode (a ``dict``). The return value of

   288         ``object_hook`` will be used instead of the ``dict``. This feature

   289         can be used to implement custom decoders (e.g. JSON-RPC class hinting).

   290 

   291         To use a custom ``JSONDecoder`` subclass, specify it with the ``cls``

   292         kwarg.

   293 

   294         """

   295         return loads(fp.read(),

   296             encoding=encoding, cls=cls, object_hook=object_hook,

   297             parse_float=parse_float, parse_int=parse_int,

   298             parse_constant=parse_constant, **kw)

   299 

   300 

   301     def loads(s, encoding=None, cls=None, object_hook=None, parse_float=None,

   302             parse_int=None, parse_constant=None, **kw):

   303         """Deserialize ``s`` (a ``str`` or ``unicode`` instance containing a JSON

   304         document) to a Python object.

   305 

   306         If ``s`` is a ``str`` instance and is encoded with an ASCII based encoding

   307         other than utf-8 (e.g. latin-1) then an appropriate ``encoding`` name

   308         must be specified. Encodings that are not ASCII based (such as UCS-2)

   309         are not allowed and should be decoded to ``unicode`` first.

   310 

   311         ``object_hook`` is an optional function that will be called with the

   312         result of any object literal decode (a ``dict``). The return value of

   313         ``object_hook`` will be used instead of the ``dict``. This feature

   314         can be used to implement custom decoders (e.g. JSON-RPC class hinting).

   315 

   316         ``parse_float``, if specified, will be called with the string

   317         of every JSON float to be decoded. By default this is equivalent to

   318         float(num_str). This can be used to use another datatype or parser

   319         for JSON floats (e.g. decimal.Decimal).

   320 

   321         ``parse_int``, if specified, will be called with the string

   322         of every JSON int to be decoded. By default this is equivalent to

   323         int(num_str). This can be used to use another datatype or parser

   324         for JSON integers (e.g. float).

   325 

   326         ``parse_constant``, if specified, will be called with one of the

   327         following strings: -Infinity, Infinity, NaN, null, true, false.

   328         This can be used to raise an exception if invalid JSON numbers

   329         are encountered.

   330 

   331         To use a custom ``JSONDecoder`` subclass, specify it with the ``cls``

   332         kwarg.

   333 

   334         """

   335         if (cls is None and encoding is None and object_hook is None and

   336                 parse_int is None and parse_float is None and

   337                 parse_constant is None and not kw):

   338             return _default_decoder.decode(s)

   339         if cls is None:

   340             cls = JSONDecoder

   341         if object_hook is not None:

   342             kw['object_hook'] = object_hook

   343         if parse_float is not None:

   344             kw['parse_float'] = parse_float

   345         if parse_int is not None:

   346             kw['parse_int'] = parse_int

   347         if parse_constant is not None:

   348             kw['parse_constant'] = parse_constant

   349         return cls(encoding=encoding, **kw).decode(s)