2 A simple, fast, extensible JSON encoder and decoder
4 JSON (JavaScript Object Notation) <http://json.org> is a subset of
5 JavaScript syntax (ECMA-262 3rd edition) used as a lightweight data
8 simplejson exposes an API familiar to uses of the standard library
9 marshal and pickle modules.
11 Encoding basic Python object hierarchies::
14 >>> simplejson.dumps(['foo', {'bar': ('baz', None, 1.0, 2)}])
15 '["foo", {"bar": ["baz", null, 1.0, 2]}]'
16 >>> print simplejson.dumps("\"foo
\bar
")
18 >>> print simplejson.dumps(u'\u1234')
20 >>> print simplejson.dumps('\\')
22 >>> print simplejson.dumps({"c": 0, "b": 0, "a": 0}, sort_keys=True)
23 {"a": 0, "b": 0, "c": 0}
24 >>> from StringIO import StringIO
26 >>> simplejson.dump(['streaming API'], io)
33 >>> simplejson.dumps([1,2,3,{'4': 5, '6': 7}], separators=(',',':'))
34 '[1,2,3,{"4":5,"6":7}]'
39 >>> print simplejson.dumps({'4': 5, '6': 7}, sort_keys=True, indent=4)
48 >>> simplejson.loads('["foo
", {"bar":["baz", null, 1.0, 2]}]')
49 [u'foo', {u'bar': [u'baz', None, 1.0, 2]}]
50 >>> simplejson.loads('"\\"foo\\bar"')
52 >>> from StringIO import StringIO
53 >>> io = StringIO('["streaming API
"]')
54 >>> simplejson.load(io)
57 Specializing JSON object decoding::
60 >>> def as_complex(dct):
61 ... if '__complex__' in dct:
62 ... return complex(dct['real'], dct['imag'])
65 >>> simplejson.loads('{"__complex__": true, "real": 1, "imag": 2}',
66 ... object_hook=as_complex)
69 >>> simplejson.loads('1.1', parse_float=decimal.Decimal)
72 Extending JSONEncoder::
75 >>> class ComplexEncoder(simplejson.JSONEncoder):
76 ... def default(self, obj):
77 ... if isinstance(obj, complex):
78 ... return [obj.real, obj.imag]
79 ... return simplejson.JSONEncoder.default(self, obj)
81 >>> dumps(2 + 1j, cls=ComplexEncoder)
83 >>> ComplexEncoder().encode(2 + 1j)
85 >>> list(ComplexEncoder().iterencode(2 + 1j))
86 ['[', '2.0', ', ', '1.0', ']']
89 Using simplejson from the shell to validate and
92 $ echo '{"json":"obj"}' | python -msimplejson
96 $ echo '{ 1.2:3.4}' | python -msimplejson
97 Expecting property name: line 1 column 2 (char 2)
99 Note that the JSON produced by this module's default settings
100 is a subset of YAML, so it may be used as a serializer for that as well.
102 __version__ = '1.9.1'
104 'dump', 'dumps', 'load', 'loads',
105 'JSONDecoder', 'JSONEncoder',
108 if __name__ == '__main__':
109 from esimplejson.decoder import JSONDecoder
110 from esimplejson.encoder import JSONEncoder
112 from decoder import JSONDecoder
113 from encoder import JSONEncoder
115 _default_encoder = JSONEncoder(
126 def dump(obj, fp, skipkeys=False, ensure_ascii=True, check_circular=True,
127 allow_nan=True, cls=None, indent=None, separators=None,
128 encoding='utf-8', default=None, **kw):
130 Serialize ``obj`` as a JSON formatted stream to ``fp`` (a
131 ``.write()``-supporting file-like object).
133 If ``skipkeys`` is ``True`` then ``dict`` keys that are not basic types
134 (``str``, ``unicode``, ``int``, ``long``, ``float``, ``bool``, ``None``)
135 will be skipped instead of raising a ``TypeError``.
137 If ``ensure_ascii`` is ``False``, then the some chunks written to ``fp``
138 may be ``unicode`` instances, subject to normal Python ``str`` to
139 ``unicode`` coercion rules. Unless ``fp.write()`` explicitly
140 understands ``unicode`` (as in ``codecs.getwriter()``) this is likely
143 If ``check_circular`` is ``False``, then the circular reference check
144 for container types will be skipped and a circular reference will
145 result in an ``OverflowError`` (or worse).
147 If ``allow_nan`` is ``False``, then it will be a ``ValueError`` to
148 serialize out of range ``float`` values (``nan``, ``inf``, ``-inf``)
149 in strict compliance of the JSON specification, instead of using the
150 JavaScript equivalents (``NaN``, ``Infinity``, ``-Infinity``).
152 If ``indent`` is a non-negative integer, then JSON array elements and object
153 members will be pretty-printed with that indent level. An indent level
154 of 0 will only insert newlines. ``None`` is the most compact representation.
156 If ``separators`` is an ``(item_separator, dict_separator)`` tuple
157 then it will be used instead of the default ``(', ', ': ')`` separators.
158 ``(',', ':')`` is the most compact JSON representation.
160 ``encoding`` is the character encoding for str instances, default is UTF-8.
162 ``default(obj)`` is a function that should return a serializable version
163 of obj or raise TypeError. The default simply raises TypeError.
165 To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the
166 ``.default()`` method to serialize additional types), specify it with
170 if (skipkeys is False and ensure_ascii is True and
171 check_circular is True and allow_nan is True and
172 cls is None and indent is None and separators is None and
173 encoding == 'utf-8' and default is None and not kw):
174 iterable = _default_encoder.iterencode(obj)
178 iterable = cls(skipkeys=skipkeys, ensure_ascii=ensure_ascii,
179 check_circular=check_circular, allow_nan=allow_nan, indent=indent,
180 separators=separators, encoding=encoding,
181 default=default, **kw).iterencode(obj)
182 # could accelerate with writelines in some versions of Python, at
183 # a debuggability cost
184 for chunk in iterable:
188 def dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True,
189 allow_nan=True, cls=None, indent=None, separators=None,
190 encoding='utf-8', default=None, **kw):
192 Serialize ``obj`` to a JSON formatted ``str``.
194 If ``skipkeys`` is ``True`` then ``dict`` keys that are not basic types
195 (``str``, ``unicode``, ``int``, ``long``, ``float``, ``bool``, ``None``)
196 will be skipped instead of raising a ``TypeError``.
198 If ``ensure_ascii`` is ``False``, then the return value will be a
199 ``unicode`` instance subject to normal Python ``str`` to ``unicode``
200 coercion rules instead of being escaped to an ASCII ``str``.
202 If ``check_circular`` is ``False``, then the circular reference check
203 for container types will be skipped and a circular reference will
204 result in an ``OverflowError`` (or worse).
206 If ``allow_nan`` is ``False``, then it will be a ``ValueError`` to
207 serialize out of range ``float`` values (``nan``, ``inf``, ``-inf``) in
208 strict compliance of the JSON specification, instead of using the
209 JavaScript equivalents (``NaN``, ``Infinity``, ``-Infinity``).
211 If ``indent`` is a non-negative integer, then JSON array elements and
212 object members will be pretty-printed with that indent level. An indent
213 level of 0 will only insert newlines. ``None`` is the most compact
216 If ``separators`` is an ``(item_separator, dict_separator)`` tuple
217 then it will be used instead of the default ``(', ', ': ')`` separators.
218 ``(',', ':')`` is the most compact JSON representation.
220 ``encoding`` is the character encoding for str instances, default is UTF-8.
222 ``default(obj)`` is a function that should return a serializable version
223 of obj or raise TypeError. The default simply raises TypeError.
225 To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the
226 ``.default()`` method to serialize additional types), specify it with
230 if (skipkeys is False and ensure_ascii is True and
231 check_circular is True and allow_nan is True and
232 cls is None and indent is None and separators is None and
233 encoding == 'utf-8' and default is None and not kw):
234 return _default_encoder.encode(obj)
238 skipkeys=skipkeys, ensure_ascii=ensure_ascii,
239 check_circular=check_circular, allow_nan=allow_nan, indent=indent,
240 separators=separators, encoding=encoding, default=default,
244 _default_decoder = JSONDecoder(encoding=None, object_hook=None)
247 def load(fp, encoding=None, cls=None, object_hook=None, parse_float=None,
248 parse_int=None, parse_constant=None, **kw):
250 Deserialize ``fp`` (a ``.read()``-supporting file-like object containing
251 a JSON document) to a Python object.
253 If the contents of ``fp`` is encoded with an ASCII based encoding other
254 than utf-8 (e.g. latin-1), then an appropriate ``encoding`` name must
255 be specified. Encodings that are not ASCII based (such as UCS-2) are
256 not allowed, and should be wrapped with
257 ``codecs.getreader(fp)(encoding)``, or simply decoded to a ``unicode``
258 object and passed to ``loads()``
260 ``object_hook`` is an optional function that will be called with the
261 result of any object literal decode (a ``dict``). The return value of
262 ``object_hook`` will be used instead of the ``dict``. This feature
263 can be used to implement custom decoders (e.g. JSON-RPC class hinting).
265 To use a custom ``JSONDecoder`` subclass, specify it with the ``cls``
268 return loads(fp.read(),
269 encoding=encoding, cls=cls, object_hook=object_hook,
270 parse_float=parse_float, parse_int=parse_int,
271 parse_constant=parse_constant, **kw)
274 def loads(s, encoding=None, cls=None, object_hook=None, parse_float=None,
275 parse_int=None, parse_constant=None, **kw):
277 Deserialize ``s`` (a ``str`` or ``unicode`` instance containing a JSON
278 document) to a Python object.
280 If ``s`` is a ``str`` instance and is encoded with an ASCII based encoding
281 other than utf-8 (e.g. latin-1) then an appropriate ``encoding`` name
282 must be specified. Encodings that are not ASCII based (such as UCS-2)
283 are not allowed and should be decoded to ``unicode`` first.
285 ``object_hook`` is an optional function that will be called with the
286 result of any object literal decode (a ``dict``). The return value of
287 ``object_hook`` will be used instead of the ``dict``. This feature
288 can be used to implement custom decoders (e.g. JSON-RPC class hinting).
290 ``parse_float``, if specified, will be called with the string
291 of every JSON float to be decoded. By default this is equivalent to
292 float(num_str). This can be used to use another datatype or parser
293 for JSON floats (e.g. decimal.Decimal).
295 ``parse_int``, if specified, will be called with the string
296 of every JSON int to be decoded. By default this is equivalent to
297 int(num_str). This can be used to use another datatype or parser
298 for JSON integers (e.g. float).
300 ``parse_constant``, if specified, will be called with one of the
301 following strings: -Infinity, Infinity, NaN, null, true, false.
302 This can be used to raise an exception if invalid JSON numbers
305 To use a custom ``JSONDecoder`` subclass, specify it with the ``cls``
308 if (cls is None and encoding is None and object_hook is None and
309 parse_int is None and parse_float is None and
310 parse_constant is None and not kw):
311 return _default_decoder.decode(s)
314 if object_hook is not None:
315 kw['object_hook'] = object_hook
316 if parse_float is not None:
317 kw['parse_float'] = parse_float
318 if parse_int is not None:
319 kw['parse_int'] = parse_int
320 if parse_constant is not None:
321 kw['parse_constant'] = parse_constant
322 return cls(encoding=encoding, **kw).decode(s)
326 # Compatibility cruft from other libraries
332 demjson, python-cjson API compatibility hook. Use loads(s) instead.
335 warnings.warn("simplejson
.loads(s
) should be used instead of
decode(s
)",
342 demjson, python-cjson compatibility hook. Use dumps(s) instead.
345 warnings.warn("simplejson
.dumps(s
) should be used instead of
encode(s
)",
352 jsonlib, JsonUtils, python-json, json-py API compatibility hook.
353 Use loads(s) instead.
356 warnings.warn("simplejson
.loads(s
) should be used instead of
read(s
)",
363 jsonlib, JsonUtils, python-json, json-py API compatibility hook.
364 Use dumps(s) instead.
367 warnings.warn("simplejson
.dumps(s
) should be used instead of
write(s
)",
374 # curl http://mochikit.com/examples/ajax_tables/domains.json | python -msimplejson
380 if len(sys.argv) == 1:
383 elif len(sys.argv) == 2:
384 infile = open(sys.argv[1], 'rb')
386 elif len(sys.argv) == 3:
387 infile = open(sys.argv[1], 'rb')
388 outfile = open(sys.argv[2], 'wb')
390 raise SystemExit("%s [infile
[outfile
]]" % (sys.argv[0],))
393 except ValueError, e:
395 dump(obj, outfile, sort_keys=True, indent=4)
399 if __name__ == '__main__':