# HG changeset patch
# User shakefu <shakefu@gmail.com>
# Date 1366232298 25200
# Wed Apr 17 13:58:18 2013 -0700
# Node ID f8b2b235bdd445fa07687adafd3c63532bd6cb94
# Parent 1eaef2b53c0754549b7768b77802f28f7a0654c4
Implement for_json kwarg; pure Python version; add tests; update documentation.
diff --git a/index.rst b/index.rst
--- a/index.rst
+++ b/index.rst
@@ -245,6 +245,13 @@
strings, to avoid comparison of heterogeneously typed objects
(since this does not work in Python 3.3+)
+ If *for_json* is true (not the default), objects with a ``for_json()``
+ method will use the return value of that method for encoding as JSON instead
+ of the object.
+
+ .. versionchanged:: 3.2.0
+ *for_json* is new in 3.2.0.
+
.. note::
JSON is not a framed protocol so unlike :mod:`pickle` or :mod:`marshal` it
@@ -252,7 +259,7 @@
container protocol to delimit them.
-.. function:: dumps(obj[, skipkeys[, ensure_ascii[, check_circular[, allow_nan[, cls[, indent[, separators[, encoding[, default[, use_decimal[, namedtuple_as_object[, tuple_as_array[, bigint_as_string[, sort_keys[, item_sort_key[, **kw]]]]]]]]]]]]]]]])
+.. function:: dumps(obj[, skipkeys[, ensure_ascii[, check_circular[, allow_nan[, cls[, indent[, separators[, encoding[, default[, use_decimal[, namedtuple_as_object[, tuple_as_array[, bigint_as_string[, sort_keys[, item_sort_key[, for_json[, **kw]]]]]]]]]]]]]]]]])
Serialize *obj* to a JSON formatted :class:`str`.
@@ -456,7 +463,7 @@
:exc:`JSONDecodeError` will be raised if the given JSON
document is not valid.
-.. class:: JSONEncoder([skipkeys[, ensure_ascii[, check_circular[, allow_nan[, sort_keys[, indent[, separators[, encoding[, default[, use_decimal[, namedtuple_as_object[, tuple_as_array[, bigint_as_string[, item_sort_key]]]]]]]]]]]]])
+.. class:: JSONEncoder([skipkeys[, ensure_ascii[, check_circular[, allow_nan[, sort_keys[, indent[, separators[, encoding[, default[, use_decimal[, namedtuple_as_object[, tuple_as_array[, bigint_as_string[, item_sort_key[, for_json]]]]]]]]]]]]]])
Extensible JSON encoder for Python data structures.
@@ -587,6 +594,12 @@
.. versionchanged:: 2.4.0
*bigint_as_string* is new in 2.4.0.
+ If *for_json* is true (default: ``False``), objects with a ``for_json()``
+ method will use the return value of that method for encoding as JSON instead
+ of the object.
+
+ .. versionchanged:: 3.2.0
+ *for_json* is new in 3.2.0.
.. method:: default(o)
diff --git a/simplejson/__init__.py b/simplejson/__init__.py
--- a/simplejson/__init__.py
+++ b/simplejson/__init__.py
@@ -142,6 +142,7 @@
tuple_as_array=True,
bigint_as_string=False,
item_sort_key=None,
+ for_json=False,
)
def dump(obj, fp, skipkeys=False, ensure_ascii=True, check_circular=True,
@@ -149,7 +150,7 @@
encoding='utf-8', default=None, use_decimal=True,
namedtuple_as_object=True, tuple_as_array=True,
bigint_as_string=False, sort_keys=False, item_sort_key=None,
- **kw):
+ for_json=False, **kw):
"""Serialize ``obj`` as a JSON formatted stream to ``fp`` (a
``.write()``-supporting file-like object).
@@ -214,6 +215,10 @@
If *sort_keys* is true (default: ``False``), the output of dictionaries
will be sorted by item.
+ If *for_json* is true (default: ``False``), objects with a ``for_json()``
+ method will use the return value of that method for encoding as JSON
+ instead of the object.
+
To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the
``.default()`` method to serialize additional types), specify it with
the ``cls`` kwarg. NOTE: You should use *default* instead of subclassing
@@ -226,7 +231,8 @@
cls is None and indent is None and separators is None and
encoding == 'utf-8' and default is None and use_decimal
and namedtuple_as_object and tuple_as_array
- and not bigint_as_string and not item_sort_key and not kw):
+ and not bigint_as_string and not item_sort_key
+ and not for_json and not kw):
iterable = _default_encoder.iterencode(obj)
else:
if cls is None:
@@ -240,6 +246,7 @@
bigint_as_string=bigint_as_string,
sort_keys=sort_keys,
item_sort_key=item_sort_key,
+ for_json=for_json,
**kw).iterencode(obj)
# could accelerate with writelines in some versions of Python, at
# a debuggability cost
@@ -252,7 +259,7 @@
encoding='utf-8', default=None, use_decimal=True,
namedtuple_as_object=True, tuple_as_array=True,
bigint_as_string=False, sort_keys=False, item_sort_key=None,
- **kw):
+ for_json=False, **kw):
"""Serialize ``obj`` to a JSON formatted ``str``.
If ``skipkeys`` is false then ``dict`` keys that are not basic types
@@ -312,6 +319,10 @@
If *sort_keys* is true (default: ``False``), the output of dictionaries
will be sorted by item.
+ If *for_json* is true (default: ``False``), objects with a ``for_json()``
+ method will use the return value of that method for encoding as JSON
+ instead of the object.
+
To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the
``.default()`` method to serialize additional types), specify it with
the ``cls`` kwarg. NOTE: You should use *default* instead of subclassing
@@ -325,7 +336,7 @@
encoding == 'utf-8' and default is None and use_decimal
and namedtuple_as_object and tuple_as_array
and not bigint_as_string and not sort_keys
- and not item_sort_key and not kw):
+ and not item_sort_key and not for_json and not kw):
return _default_encoder.encode(obj)
if cls is None:
cls = JSONEncoder
@@ -339,6 +350,7 @@
bigint_as_string=bigint_as_string,
sort_keys=sort_keys,
item_sort_key=item_sort_key,
+ for_json=for_json,
**kw).encode(obj)
diff --git a/simplejson/_speedups.c b/simplejson/_speedups.c
--- a/simplejson/_speedups.c
+++ b/simplejson/_speedups.c
@@ -170,6 +170,7 @@
int bigint_as_string;
PyObject *item_sort_key;
PyObject *item_sort_kw;
+ int for_json;
} PyEncoderObject;
static PyMemberDef encoder_members[] = {
@@ -2587,22 +2588,22 @@
encoder_init(PyObject *self, PyObject *args, PyObject *kwds)
{
/* initialize Encoder object */
- static char *kwlist[] = {"markers", "default", "encoder", "indent", "key_separator", "item_separator", "sort_keys", "skipkeys", "allow_nan", "key_memo", "use_decimal", "namedtuple_as_object", "tuple_as_array", "bigint_as_string", "item_sort_key", "encoding", "Decimal", NULL};
+ static char *kwlist[] = {"markers", "default", "encoder", "indent", "key_separator", "item_separator", "sort_keys", "skipkeys", "allow_nan", "key_memo", "use_decimal", "namedtuple_as_object", "tuple_as_array", "bigint_as_string", "item_sort_key", "encoding", "Decimal", "for_json", NULL};
PyEncoderObject *s;
PyObject *markers, *defaultfn, *encoder, *indent, *key_separator;
PyObject *item_separator, *sort_keys, *skipkeys, *allow_nan, *key_memo;
PyObject *use_decimal, *namedtuple_as_object, *tuple_as_array;
- PyObject *bigint_as_string, *item_sort_key, *encoding, *Decimal;
+ PyObject *bigint_as_string, *item_sort_key, *encoding, *Decimal, *for_json;
assert(PyEncoder_Check(self));
s = (PyEncoderObject *)self;
- if (!PyArg_ParseTupleAndKeywords(args, kwds, "OOOOOOOOOOOOOOOOO:make_encoder", kwlist,
+ if (!PyArg_ParseTupleAndKeywords(args, kwds, "OOOOOOOOOOOOOOOOOO:make_encoder", kwlist,
&markers, &defaultfn, &encoder, &indent, &key_separator, &item_separator,
&sort_keys, &skipkeys, &allow_nan, &key_memo, &use_decimal,
&namedtuple_as_object, &tuple_as_array, &bigint_as_string,
- &item_sort_key, &encoding, &Decimal))
+ &item_sort_key, &encoding, &Decimal, &for_json))
return -1;
s->markers = markers;
@@ -2654,6 +2655,7 @@
s->sort_keys = sort_keys;
s->item_sort_key = item_sort_key;
s->Decimal = Decimal;
+ s->for_json = PyObject_IsTrue(for_json);
Py_INCREF(s->markers);
Py_INCREF(s->defaultfn);
@@ -2817,7 +2819,7 @@
if (encoded != NULL)
rv = _steal_accumulate(rval, encoded);
}
- else if (_has_for_json_hook(obj)) {
+ else if (s->for_json && _has_for_json_hook(obj)) {
PyObject *newobj;
if (Py_EnterRecursiveCall(" while encoding a JSON object"))
return rv;
diff --git a/simplejson/encoder.py b/simplejson/encoder.py
--- a/simplejson/encoder.py
+++ b/simplejson/encoder.py
@@ -121,7 +121,7 @@
indent=None, separators=None, encoding='utf-8', default=None,
use_decimal=True, namedtuple_as_object=True,
tuple_as_array=True, bigint_as_string=False,
- item_sort_key=None):
+ item_sort_key=None, for_json=False):
"""Constructor for JSONEncoder, with sensible defaults.
If skipkeys is false, then it is a TypeError to attempt
@@ -183,6 +183,11 @@
If specified, item_sort_key is a callable used to sort the items in
each dictionary. This is useful if you want to sort items other than
in alphabetical order by key.
+
+ If for_json is true (not the default), objects with a ``for_json()``
+ method will use the return value of that method for encoding as JSON
+ instead of the object.
+
"""
self.skipkeys = skipkeys
@@ -195,6 +200,7 @@
self.tuple_as_array = tuple_as_array
self.bigint_as_string = bigint_as_string
self.item_sort_key = item_sort_key
+ self.for_json = for_json
if indent is not None and not isinstance(indent, string_types):
indent = indent * ' '
self.indent = indent
@@ -312,7 +318,7 @@
self.namedtuple_as_object, self.tuple_as_array,
self.bigint_as_string, self.item_sort_key,
self.encoding,
- Decimal)
+ Decimal, self.for_json)
else:
_iterencode = _make_iterencode(
markers, self.default, _encoder, self.indent, floatstr,
@@ -320,7 +326,7 @@
self.skipkeys, _one_shot, self.use_decimal,
self.namedtuple_as_object, self.tuple_as_array,
self.bigint_as_string, self.item_sort_key,
- self.encoding,
+ self.encoding, self.for_json,
Decimal=Decimal)
try:
return _iterencode(o, 0)
@@ -358,7 +364,7 @@
def _make_iterencode(markers, _default, _encoder, _indent, _floatstr,
_key_separator, _item_separator, _sort_keys, _skipkeys, _one_shot,
_use_decimal, _namedtuple_as_object, _tuple_as_array,
- _bigint_as_string, _item_sort_key, _encoding,
+ _bigint_as_string, _item_sort_key, _encoding, _for_json,
## HACK: hand-optimized bytecode; turn globals into locals
_PY3=PY3,
ValueError=ValueError,
@@ -422,7 +428,10 @@
yield buf + str(value)
else:
yield buf
- if isinstance(value, list):
+ for_json = _for_json and getattr(value, 'for_json', None)
+ if for_json and callable(for_json):
+ chunks = _iterencode(for_json(), _current_indent_level)
+ elif isinstance(value, list):
chunks = _iterencode_list(value, _current_indent_level)
else:
_asdict = _namedtuple_as_object and getattr(value, '_asdict', None)
@@ -532,7 +541,10 @@
elif _use_decimal and isinstance(value, Decimal):
yield str(value)
else:
- if isinstance(value, list):
+ for_json = _for_json and getattr(value, 'for_json', None)
+ if for_json and callable(for_json):
+ chunks = _iterencode(for_json(), _current_indent_level)
+ elif isinstance(value, list):
chunks = _iterencode_list(value, _current_indent_level)
else:
_asdict = _namedtuple_as_object and getattr(value, '_asdict', None)
@@ -571,32 +583,38 @@
else ('"' + str(o) + '"'))
elif isinstance(o, float):
yield _floatstr(o)
- elif isinstance(o, list):
- for chunk in _iterencode_list(o, _current_indent_level):
- yield chunk
else:
- _asdict = _namedtuple_as_object and getattr(o, '_asdict', None)
- if _asdict and callable(_asdict):
- for chunk in _iterencode_dict(_asdict(), _current_indent_level):
+ for_json = _for_json and getattr(o, 'for_json', None)
+ if for_json and callable(for_json):
+ for chunk in _iterencode(for_json(), _current_indent_level):
yield chunk
- elif (_tuple_as_array and isinstance(o, tuple)):
+ elif isinstance(o, list):
for chunk in _iterencode_list(o, _current_indent_level):
yield chunk
- elif isinstance(o, dict):
- for chunk in _iterencode_dict(o, _current_indent_level):
- yield chunk
- elif _use_decimal and isinstance(o, Decimal):
- yield str(o)
else:
- if markers is not None:
- markerid = id(o)
- if markerid in markers:
- raise ValueError("Circular reference detected")
- markers[markerid] = o
- o = _default(o)
- for chunk in _iterencode(o, _current_indent_level):
- yield chunk
- if markers is not None:
- del markers[markerid]
+ _asdict = _namedtuple_as_object and getattr(o, '_asdict', None)
+ if _asdict and callable(_asdict):
+ for chunk in _iterencode_dict(_asdict(),
+ _current_indent_level):
+ yield chunk
+ elif (_tuple_as_array and isinstance(o, tuple)):
+ for chunk in _iterencode_list(o, _current_indent_level):
+ yield chunk
+ elif isinstance(o, dict):
+ for chunk in _iterencode_dict(o, _current_indent_level):
+ yield chunk
+ elif _use_decimal and isinstance(o, Decimal):
+ yield str(o)
+ else:
+ if markers is not None:
+ markerid = id(o)
+ if markerid in markers:
+ raise ValueError("Circular reference detected")
+ markers[markerid] = o
+ o = _default(o)
+ for chunk in _iterencode(o, _current_indent_level):
+ yield chunk
+ if markers is not None:
+ del markers[markerid]
return _iterencode
diff --git a/simplejson/tests/test_for_json.py b/simplejson/tests/test_for_json.py
new file mode 100644
--- /dev/null
+++ b/simplejson/tests/test_for_json.py
@@ -0,0 +1,126 @@
+import unittest
+import simplejson as json
+
+
+class ForJson(object):
+ def for_json(self):
+ return {'for_json': 1}
+
+
+class NestedForJson(object):
+ def for_json(self):
+ return {'nested': ForJson()}
+
+
+class ForJsonList(object):
+ def for_json(self):
+ return ['list']
+
+
+class DictForJson(dict):
+ def for_json(self):
+ return {'alpha': 1}
+
+
+class ListForJson(list):
+ def for_json(self):
+ return ['list']
+
+
+class TestForJsonWithSpeedups(unittest.TestCase):
+ def setUp(self):
+ if not json.encoder.c_make_encoder:
+ raise unittest.SkipTest("No speedups.")
+
+ @staticmethod
+ def _dump(obj):
+ return json.dumps(obj, for_json=True)
+
+ def test_for_json_encodes_stand_alone_object(self):
+ self.assertEqual(self._dump(ForJson()), '{"for_json": 1}')
+
+ def test_for_json_encodes_object_nested_in_dict(self):
+ self.assertEqual(self._dump({'hooray': ForJson()}), '{"hooray": '
+ '{"for_json": 1}}')
+
+ def test_for_json_encodes_object_nested_in_list_within_dict(self):
+ self.assertEqual(self._dump({'list': [0, ForJson(), 2, 3]}),
+ '{"list": [0, {"for_json": 1}, 2, 3]}')
+
+ def test_for_json_encodes_object_nested_within_object(self):
+ self.assertEqual(self._dump(NestedForJson()),
+ '{"nested": {"for_json": 1}}')
+
+ def test_for_json_encodes_list(self):
+ self.assertEqual(self._dump(ForJsonList()), '["list"]')
+
+ def test_for_json_encodes_list_within_object(self):
+ self.assertEqual(self._dump({'nested': ForJsonList()}),
+ '{"nested": ["list"]}')
+
+ def test_for_json_encodes_dict_subclass(self):
+ self.assertEqual(self._dump(DictForJson(a=1)), '{"alpha": 1}')
+
+ def test_for_json_encodes_list_subclass(self):
+ self.assertEqual(self._dump(ListForJson(['l'])), '["list"]')
+
+ def tset_for_json_ignored_if_not_true_with_dict_subclass(self):
+ self.assertEqual(json.dumps(DictForJson(a=1)), '{"a": 1}')
+
+ def test_for_json_ignored_if_not_true_with_list_subclass(self):
+ self.assertEqual(json.dumps(ListForJson(['l'])), '["l"]')
+
+ def test_raises_typeerror_if_for_json_not_true_with_object(self):
+ self.assertRaises(TypeError, json.dumps, ForJson())
+
+
+class TestForJsonWithoutSpeedups(unittest.TestCase):
+ def setUp(self):
+ if json.encoder.c_make_encoder:
+ json._toggle_speedups(False)
+
+ def tearDown(self):
+ if json.encoder.c_make_encoder:
+ json._toggle_speedups(True)
+
+ @staticmethod
+ def _dump(obj):
+ return json.dumps(obj, for_json=True)
+
+ def test_for_json_encodes_stand_alone_object(self):
+ self.assertEqual(self._dump(ForJson()), '{"for_json": 1}')
+
+ def test_for_json_encodes_object_nested_in_dict(self):
+ self.assertEqual(self._dump({'hooray': ForJson()}), '{"hooray": '
+ '{"for_json": 1}}')
+
+ def test_for_json_encodes_object_nested_in_list_within_dict(self):
+ self.assertEqual(self._dump({'list': [0, ForJson(), 2, 3]}),
+ '{"list": [0, {"for_json": 1}, 2, 3]}')
+
+ def test_for_json_encodes_object_nested_within_object(self):
+ self.assertEqual(self._dump(NestedForJson()),
+ '{"nested": {"for_json": 1}}')
+
+ def test_for_json_encodes_list(self):
+ self.assertEqual(self._dump(ForJsonList()), '["list"]')
+
+ def test_for_json_encodes_list_within_object(self):
+ self.assertEqual(self._dump({'nested': ForJsonList()}),
+ '{"nested": ["list"]}')
+
+ def test_for_json_encodes_dict_subclass(self):
+ self.assertEqual(self._dump(DictForJson(a=1)), '{"alpha": 1}')
+
+ def test_for_json_encodes_list_subclass(self):
+ self.assertEqual(self._dump(ListForJson(['l'])), '["list"]')
+
+ def tset_for_json_ignored_if_not_true_with_dict_subclass(self):
+ self.assertEqual(json.dumps(DictForJson(a=1)), '{"a": 1}')
+
+ def test_for_json_ignored_if_not_true_with_list_subclass(self):
+ self.assertEqual(json.dumps(ListForJson(['l'])), '["l"]')
+
+ def test_raises_typeerror_if_for_json_not_true_with_object(self):
+ self.assertRaises(TypeError, json.dumps, ForJson())
+