Extension docs build script, gyp target and PRESUBMIT.PY check

third_party/simplejson/index.rst

+:mod:`simplejson` --- JSON encoder and decoder
+==============================================
+
+.. module:: simplejson
+   :synopsis: Encode and decode the JSON format.
+.. moduleauthor:: Bob Ippolito <bob@redivi.com>
+.. sectionauthor:: Bob Ippolito <bob@redivi.com>
+
+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 with Python 2.4 and 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 StringIO import StringIO
+    >>> io = StringIO()
+    >>> json.dump(['streaming API'], io)
+    >>> io.getvalue()
+    '["streaming API"]'
+
+Compact encoding::
+
+    >>> import simplejson as json
+    >>> json.dumps([1,2,3,{'4': 5, '6': 7}], separators=(',',':'))
+    '[1,2,3,{"4":5,"6":7}]'
+
+Pretty printing::
+
+    >>> import simplejson as json
+    >>> s = json.dumps({'4': 5, '6': 7}, sort_keys=True, indent=4)
+    >>> print '\n'.join([l.rstrip() for l in  s.splitlines()])
+    {
+        "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 StringIO 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)
+    >>> import decimal
+    >>> json.loads('1.1', parse_float=decimal.Decimal) == 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(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]'
+
+
+.. highlight:: none
+
+Using :mod:`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 2 (char 2)
+
+.. highlight:: python
+
+.. note::
+
+   The JSON produced by this module's default settings is a subset of
+   YAML, so it may be used as a serializer for that as well.
+
+
+Basic Usage
+-----------
+
+.. function:: dump(obj, fp[, skipkeys[, ensure_ascii[, check_circular[, allow_nan[, cls[, indent[, separators[, encoding[, default[, **kw]]]]]]]]]])
+
+   Serialize *obj* as a JSON formatted stream to *fp* (a ``.write()``-supporting
+   file-like object).
+
+   If *skipkeys* is true (default: ``False``), then dict keys that are not
+   of a basic type (:class:`str`, :class:`unicode`, :class:`int`, :class:`long`,
+   :class:`float`, :class:`bool`, ``None``) will be skipped instead of raising a
+   :exc:`TypeError`.
+
+   If *ensure_ascii* is false (default: ``True``), then some chunks written
+   to *fp* may be :class:`unicode` instances, subject to normal Python
+   :class:`str` to :class:`unicode` coercion rules.  Unless ``fp.write()``
+   explicitly understands :class:`unicode` (as in :func:`codecs.getwriter`) this
+   is likely to cause an error. It's best to leave the default settings, because
+   they are safe and it is highly optimized.
+
+   If *check_circular* is false (default: ``True``), then the circular
+   reference check for container types will be skipped and a circular reference
+   will result in an :exc:`OverflowError` (or worse).
+
+   If *allow_nan* is false (default: ``True``), then it will be a
+   :exc:`ValueError` to serialize out of range :class:`float` values (``nan``,
+   ``inf``, ``-inf``) in strict compliance of the JSON specification.
+   If *allow_nan* is true, their JavaScript equivalents will be used
+   (``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`` (the default) selects the most compact
+   representation.
+
+   If specified, *separators* should be an ``(item_separator, dict_separator)`` 
+   tuple.  By default, ``(', ', ': ')`` are used.  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'``.
+
+   If specified, *default* should be a function that gets called for objects
+   that can't otherwise be serialized.  It should return a JSON encodable
+   version of the object or raise a :exc:`TypeError`.  If not specified,
+   :exc:`TypeError` is always raised in those cases.
+
+   To use a custom :class:`JSONEncoder` subclass (e.g. one that overrides the
+   :meth:`default` method to serialize additional types), specify it with the
+   *cls* kwarg.
+
+    .. note::
+
+        JSON is not a framed protocol so unlike :mod:`pickle` or :mod:`marshal` it
+        does not make sense to serialize more than one JSON document without some
+        container protocol to delimit them.
+
+
+.. function:: dumps(obj[, skipkeys[, ensure_ascii[, check_circular[, allow_nan[, cls[, indent[, separators[, encoding[, default[, **kw]]]]]]]]]])
+
+   Serialize *obj* to a JSON formatted :class:`str`.
+
+   If *ensure_ascii* is false, then the return value will be a
+   :class:`unicode` instance.  The other arguments have the same meaning as in
+   :func:`dump`. Note that the default *ensure_ascii* setting has much
+   better performance.
+
+
+.. function:: load(fp[, encoding[, cls[, object_hook[, parse_float[, parse_int[, parse_constant[, **kw]]]]]]])
+
+   Deserialize *fp* (a ``.read()``-supporting file-like object containing a JSON
+   document) to a Python object.
+
+   If the contents of *fp* are encoded with an ASCII based encoding other than
+   UTF-8 (e.g. latin-1), then an appropriate *encoding* name must be specified.
+   Encodings that are not ASCII based (such as UCS-2) are not allowed, and
+   should be wrapped with ``codecs.getreader(fp)(encoding)``, or simply decoded
+   to a :class:`unicode` object and passed to :func:`loads`. The default
+   setting of ``'utf-8'`` is fastest and should be using whenever possible.
+
+   *object_hook* is an optional function that will be called with the result of
+   any object literal decode (a :class:`dict`).  The return value of
+   *object_hook* will be used instead of the :class:`dict`.  This feature can be used
+   to implement custom decoders (e.g. JSON-RPC class hinting).
+
+   *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.
+
+   To use a custom :class:`JSONDecoder` subclass, specify it with the ``cls``
+   kwarg.  Additional keyword arguments will be passed to the constructor of the
+   class.
+
+    .. note::
+
+        :func:`load` will read the rest of the file-like object as a string and
+        then call :func:`loads`. It does not stop at the end of the first valid
+        JSON document it finds and it will raise an error if there is anything
+        other than whitespace after the document. Except for files containing
+        only one JSON document, it is recommended to use :func:`loads`.
+
+
+.. function:: loads(s[, encoding[, cls[, object_hook[, parse_float[, parse_int[, parse_constant[, **kw]]]]]]])
+
+   Deserialize *s* (a :class:`str` or :class:`unicode` instance containing a JSON
+   document) to a Python object.
+
+   If *s* is a :class:`str` instance and is encoded with an ASCII based encoding
+   other than UTF-8 (e.g. latin-1), then an appropriate *encoding* name must be
+   specified.  Encodings that are not ASCII based (such as UCS-2) are not
+   allowed and should be decoded to :class:`unicode` first.
+
+   The other arguments have the same meaning as in :func:`load`.
+
+
+Encoders and decoders
+---------------------
+
+.. class:: JSONDecoder([encoding[, object_hook[, parse_float[, parse_int[, parse_constant[, strict]]]]]])
+
+   Simple JSON decoder.
+
+   Performs the following translations in decoding by default:
+
+   +---------------+-------------------+
+   | JSON          | Python            |
+   +===============+===================+
+   | object        | dict              |
+   +---------------+-------------------+
+   | array         | list              |
+   +---------------+-------------------+
+   | string        | unicode           |
+   +---------------+-------------------+
+   | number (int)  | int, long         |
+   +---------------+-------------------+
+   | number (real) | float             |
+   +---------------+-------------------+
+   | true          | True              |
+   +---------------+-------------------+
+   | false         | False             |
+   +---------------+-------------------+
+   | null          | None              |
+   +---------------+-------------------+
+
+   It also understands ``NaN``, ``Infinity``, and ``-Infinity`` as their
+   corresponding ``float`` values, which is outside the JSON spec.
+
+   *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).
+
+   *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.
+
+   *strict* controls the parser's behavior when it encounters an invalid
+   control character in a string. The default setting of ``True`` means that
+   unescaped control characters are parse errors, if ``False`` then control
+   characters will be allowed in strings.
+
+   .. method:: decode(s)
+
+      Return the Python representation of *s* (a :class:`str` or
+      :class:`unicode` instance containing a JSON document)
+
+   .. method:: raw_decode(s)
+
+      Decode a JSON document from *s* (a :class:`str` or :class:`unicode`
+      beginning with a JSON document) and return a 2-tuple of the Python
+      representation and the index in *s* where the document ended.
+
+      This can be used to decode a JSON document from a string that may have
+      extraneous data at the end.
+
+
+.. class:: JSONEncoder([skipkeys[, ensure_ascii[, check_circular[, allow_nan[, sort_keys[, indent[, separators[, encoding[, default]]]]]]]]])
+
+   Extensible JSON encoder for Python data structures.
+
+   Supports the following objects and types by default:
+
+   +-------------------+---------------+
+   | Python            | JSON          |
+   +===================+===============+
+   | dict              | object        |
+   +-------------------+---------------+
+   | list, tuple       | array         |
+   +-------------------+---------------+
+   | str, unicode      | string        |
+   +-------------------+---------------+
+   | int, long, float  | number        |
+   +-------------------+---------------+
+   | True              | true          |
+   +-------------------+---------------+
+   | False             | false         |
+   +-------------------+---------------+
+   | None              | null          |
+   +-------------------+---------------+
+
+   To extend this to recognize other objects, subclass and implement a
+   :meth:`default` method with another method that returns a serializable object
+   for ``o`` if possible, otherwise it should call the superclass implementation
+   (to raise :exc:`TypeError`).
+
+   If *skipkeys* is false (the default), then it is a :exc:`TypeError` to
+   attempt encoding of keys that are not str, int, long, float or None.  If
+   *skipkeys* is true, such items are simply skipped.
+
+   If *ensure_ascii* is true (the default), the output is guaranteed to be
+   :class:`str` objects with all incoming unicode characters escaped.  If
+   *ensure_ascii* is false, the output will be a unicode object.
+
+   If *check_circular* is false (the default), then lists, dicts, and custom
+   encoded objects will be checked for circular references during encoding to
+   prevent an infinite recursion (which would cause an :exc:`OverflowError`).
+   Otherwise, no such check takes place.
+
+   If *allow_nan* is true (the default), then ``NaN``, ``Infinity``, and
+   ``-Infinity`` will be encoded as such.  This behavior is not JSON
+   specification compliant, but is consistent with most JavaScript based
+   encoders and decoders.  Otherwise, it will be a :exc:`ValueError` to encode
+   such floats.
+
+   If *sort_keys* is true (the default), then the output of dictionaries
+   will be sorted by key; this is useful for regression tests to ensure that
+   JSON serializations can be compared on a day-to-day basis.
+
+   If *indent* is a non-negative integer (it is ``None`` by default), 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.  By default, ``(', ', ': ')`` are used.  To get the most compact JSON
+   representation, you should specify ``(',', ':')`` to eliminate whitespace.
+
+   If specified, *default* should be a function that gets called for objects
+   that can't otherwise be serialized.  It should return a JSON encodable
+   version of the object or raise a :exc:`TypeError`.
+
+   If *encoding* is not ``None``, then all input strings will be transformed
+   into unicode using that encoding prior to JSON-encoding.  The default is
+   ``'utf-8'``.
+
+
+   .. method:: default(o)
+
+      Implement this method in a subclass such that it returns a serializable
+      object for *o*, or calls the base implementation (to raise a
+      :exc:`TypeError`).
+
+      For example, to support arbitrary iterators, you could implement default
+      like this::
+
+         def default(self, o):
+            try:
+                iterable = iter(o)
+            except TypeError:
+                pass
+            else:
+                return list(iterable)
+            return JSONEncoder.default(self, o)
+
+
+   .. method:: encode(o)
+
+      Return a JSON string representation of a Python data structure, *o*.  For
+      example::
+
+        >>> import simplejson as json
+        >>> json.JSONEncoder().encode({"foo": ["bar", "baz"]})
+        '{"foo": ["bar", "baz"]}'
+
+
+   .. method:: iterencode(o)
+
+      Encode the given object, *o*, and yield each string representation as
+      available.  For example::
+
+            for chunk in JSONEncoder().iterencode(bigobject):
+                mysocket.write(chunk)
+
+      Note that :meth:`encode` has much better performance than
+      :meth:`iterencode`.