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Diffstat (limited to 'simplejson/__init__.py')
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diff --git a/simplejson/__init__.py b/simplejson/__init__.py new file mode 100644 index 0000000..be9e87a --- /dev/null +++ b/simplejson/__init__.py @@ -0,0 +1,389 @@ +r""" +A simple, fast, extensible JSON encoder and decoder + +JSON (JavaScript Object Notation) <http://json.org> is a subset of +JavaScript syntax (ECMA-262 3rd edition) used as a lightweight data +interchange format. + +simplejson exposes an API familiar to uses of the standard library +marshal and pickle modules. + +Encoding basic Python object hierarchies:: + + >>> import simplejson + >>> simplejson.dumps(['foo', {'bar': ('baz', None, 1.0, 2)}]) + '["foo", {"bar": ["baz", null, 1.0, 2]}]' + >>> print simplejson.dumps("\"foo\bar") + "\"foo\bar" + >>> print simplejson.dumps(u'\u1234') + "\u1234" + >>> print simplejson.dumps('\\') + "\\" + >>> print simplejson.dumps({"c": 0, "b": 0, "a": 0}, sort_keys=True) + {"a": 0, "b": 0, "c": 0} + >>> from StringIO import StringIO + >>> io = StringIO() + >>> simplejson.dump(['streaming API'], io) + >>> io.getvalue() + '["streaming API"]' + +Compact encoding:: + + >>> import simplejson + >>> simplejson.dumps([1,2,3,{'4': 5, '6': 7}], separators=(',',':')) + '[1,2,3,{"4":5,"6":7}]' + +Pretty printing:: + + >>> import simplejson + >>> print simplejson.dumps({'4': 5, '6': 7}, sort_keys=True, indent=4) + { + "4": 5, + "6": 7 + } + +Decoding JSON:: + + >>> import simplejson + >>> simplejson.loads('["foo", {"bar":["baz", null, 1.0, 2]}]') + [u'foo', {u'bar': [u'baz', None, 1.0, 2]}] + >>> simplejson.loads('"\\"foo\\bar"') + u'"foo\x08ar' + >>> from StringIO import StringIO + >>> io = StringIO('["streaming API"]') + >>> simplejson.load(io) + [u'streaming API'] + +Specializing JSON object decoding:: + + >>> import simplejson + >>> def as_complex(dct): + ... if '__complex__' in dct: + ... return complex(dct['real'], dct['imag']) + ... return dct + ... + >>> simplejson.loads('{"__complex__": true, "real": 1, "imag": 2}', + ... object_hook=as_complex) + (1+2j) + >>> import decimal + >>> simplejson.loads('1.1', parse_float=decimal.Decimal) + decimal.Decimal(1.1) + +Extending JSONEncoder:: + + >>> import simplejson + >>> class ComplexEncoder(simplejson.JSONEncoder): + ... def default(self, obj): + ... if isinstance(obj, complex): + ... return [obj.real, obj.imag] + ... return simplejson.JSONEncoder.default(self, obj) + ... + >>> dumps(2 + 1j, cls=ComplexEncoder) + '[2.0, 1.0]' + >>> ComplexEncoder().encode(2 + 1j) + '[2.0, 1.0]' + >>> list(ComplexEncoder().iterencode(2 + 1j)) + ['[', '2.0', ', ', '1.0', ']'] + + +Using simplejson from the shell to validate and +pretty-print:: + + $ echo '{"json":"obj"}' | python -msimplejson + { + "json": "obj" + } + $ echo '{ 1.2:3.4}' | python -msimplejson + Expecting property name: line 1 column 2 (char 2) + +Note that 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. +""" +__version__ = '1.8.1' +__all__ = [ + 'dump', 'dumps', 'load', 'loads', + 'JSONDecoder', 'JSONEncoder', +] + +if __name__ == '__main__': + from simplejson.decoder import JSONDecoder + from simplejson.encoder import JSONEncoder +else: + 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, + encoding='utf-8', + default=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, **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 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 ``separators`` is an ``(item_separator, dict_separator)`` tuple + then it will be used instead of the default ``(', ', ': ')`` separators. + ``(',', ':')`` is the most compact JSON representation. + + ``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. + + To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the + ``.default()`` method to serialize additional types), specify it with + the ``cls`` kwarg. + """ + # cached encoder + if (skipkeys is False and ensure_ascii is True and + check_circular is True and allow_nan is True and + cls is None and indent is None and separators is None and + encoding == 'utf-8' and default 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, **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, **kw): + """ + Serialize ``obj`` to a JSON formatted ``str``. + + 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 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 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 ``separators`` is an ``(item_separator, dict_separator)`` tuple + then it will be used instead of the default ``(', ', ': ')`` separators. + ``(',', ':')`` is the most compact JSON representation. + + ``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. + + To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the + ``.default()`` method to serialize additional types), specify it with + the ``cls`` kwarg. + """ + # cached encoder + if (skipkeys is False and ensure_ascii is True and + check_circular is True and allow_nan is True and + cls is None and indent is None and separators is None and + encoding == 'utf-8' and default 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, + **kw).encode(obj) + +_default_decoder = JSONDecoder(encoding=None, object_hook=None) + +def load(fp, encoding=None, cls=None, object_hook=None, parse_float=None, + parse_int=None, parse_constant=None, **kw): + """ + Deserialize ``fp`` (a ``.read()``-supporting file-like object containing + a JSON document) to a Python object. + + If the contents of ``fp`` 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 wrapped with + ``codecs.getreader(fp)(encoding)``, or simply decoded to a ``unicode`` + object and passed to ``loads()`` + + ``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). + + To use a custom ``JSONDecoder`` subclass, specify it with the ``cls`` + kwarg. + """ + return loads(fp.read(), + encoding=encoding, cls=cls, object_hook=object_hook, + parse_float=parse_float, parse_int=parse_int, + parse_constant=parse_constant, **kw) + +def loads(s, encoding=None, cls=None, object_hook=None, parse_float=None, + parse_int=None, parse_constant=None, **kw): + """ + Deserialize ``s`` (a ``str`` or ``unicode`` instance containing a JSON + document) to a Python object. + + If ``s`` is a ``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 ``unicode`` first. + + ``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). + + ``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. + """ + 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 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 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(encoding=encoding, **kw).decode(s) + +# +# Compatibility cruft from other libraries +# + +def decode(s): + """ + demjson, python-cjson API compatibility hook. Use loads(s) instead. + """ + import warnings + warnings.warn("simplejson.loads(s) should be used instead of decode(s)", + DeprecationWarning) + return loads(s) + +def encode(obj): + """ + demjson, python-cjson compatibility hook. Use dumps(s) instead. + """ + import warnings + warnings.warn("simplejson.dumps(s) should be used instead of encode(s)", + DeprecationWarning) + return dumps(obj) + +def read(s): + """ + jsonlib, JsonUtils, python-json, json-py API compatibility hook. + Use loads(s) instead. + """ + import warnings + warnings.warn("simplejson.loads(s) should be used instead of read(s)", + DeprecationWarning) + return loads(s) + +def write(obj): + """ + jsonlib, JsonUtils, python-json, json-py API compatibility hook. + Use dumps(s) instead. + """ + import warnings + warnings.warn("simplejson.dumps(s) should be used instead of write(s)", + DeprecationWarning) + return dumps(obj) + +# +# Pretty printer: +# curl http://mochikit.com/examples/ajax_tables/domains.json | python -msimplejson +# + +def main(): + import sys + if len(sys.argv) == 1: + infile = sys.stdin + outfile = sys.stdout + elif len(sys.argv) == 2: + infile = open(sys.argv[1], 'rb') + outfile = sys.stdout + elif len(sys.argv) == 3: + infile = open(sys.argv[1], 'rb') + outfile = open(sys.argv[2], 'wb') + else: + raise SystemExit("%s [infile [outfile]]" % (sys.argv[0],)) + try: + obj = load(infile) + except ValueError, e: + raise SystemExit(e) + dump(obj, outfile, sort_keys=True, indent=4) + outfile.write('\n') + +if __name__ == '__main__': + main() |