Merge branch 'item_sort_key'v2.5.0

8 files changed, 153 insertions, 37 deletions

diff --git a/CHANGES.txt b/CHANGES.txt
index 94e4434..b03ba76 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,3 +1,8 @@
+Version 2.5.0 released 2012-03-29
+
+* New item_sort_key option for encoder to allow fine grained control of sorted
+  output
+
 Version 2.4.0 released 2012-03-06
 
 * New bigint_as_string option for encoder to trade JavaScript number precision
diff --git a/conf.py b/conf.py
index 150c7cc..4614307 100644
--- a/conf.py
+++ b/conf.py
@@ -42,9 +42,9 @@ copyright = '2011, Bob Ippolito'
 # other places throughout the built documents.
 #
 # The short X.Y version.
-version = '2.4'
+version = '2.5'
 # The full version, including alpha/beta/rc tags.
-release = '2.4.0'
+release = '2.5.0'
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used:
diff --git a/index.rst b/index.rst
index fd92f4d..c63f57f 100644
--- a/index.rst
+++ b/index.rst
@@ -129,7 +129,7 @@ Using :mod:`simplejson.tool` from the shell to validate and pretty-print::
 Basic Usage
 -----------
 
-.. function:: dump(obj, fp[, skipkeys[, ensure_ascii[, check_circular[, allow_nan[, cls[, indent[, separators[, encoding[, default[, use_decimal[, namedtuple_as_object[, tuple_as_array[, **kw]]]]]]]]]]]]])
+.. function:: dump(obj, fp[, 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]]]]]]]]]]]]]]]])
 
    Serialize *obj* as a JSON formatted stream to *fp* (a ``.write()``-supporting
    file-like object).
@@ -189,22 +189,42 @@ Basic Usage
    .. versionchanged:: 2.2.0
       The default of *use_decimal* changed to ``True`` in 2.2.0.
 
-  If *namedtuple_as_object* is true (default: ``True``),
-  objects with ``_asdict()`` methods will be encoded
-  as JSON objects.
+   If *namedtuple_as_object* is true (default: ``True``),
+   objects with ``_asdict()`` methods will be encoded
+   as JSON objects.
 
-  .. versionchanged:: 2.2.0
-    *namedtuple_as_object* is new in 2.2.0.
+   .. versionchanged:: 2.2.0
+     *namedtuple_as_object* is new in 2.2.0.
 
-  .. versionchanged:: 2.3.0
-    *namedtuple_as_object* no longer requires that these objects be
-    subclasses of :class:`tuple`.
+   .. versionchanged:: 2.3.0
+     *namedtuple_as_object* no longer requires that these objects be
+     subclasses of :class:`tuple`.
+
+   If *tuple_as_array* is true (default: ``True``),
+   :class:`tuple` (and subclasses) will be encoded as JSON arrays.
 
-  If *tuple_as_array* is true (default: ``True``),
-  :class:`tuple` (and subclasses) will be encoded as JSON arrays.
+   .. versionchanged:: 2.2.0
+     *tuple_as_array* is new in 2.2.0.
 
-  .. versionchanged:: 2.2.0
-    *tuple_as_array* is new in 2.2.0.
+   If *bigint_as_string* is true (default: ``False``), :class:`int`` ``2**53``
+   and higher or lower than ``-2**53`` will be encoded as strings. This is to
+   avoid the rounding that happens in Javascript otherwise. Note that this
+   option loses type information, so use with extreme caution.
+
+   .. versionchanged:: 2.4.0
+     *bigint_as_string* is new in 2.4.0.
+
+   If *sort_keys* is true (not 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 *item_sort_key* is a callable (not the default), then the output of
+   dictionaries will be sorted with it. The callable will be used like this:
+   ``sorted(dct.items(), key=item_sort_key)``. This option takes precedence
+   over *sort_keys*.
+
+   .. versionchanged:: 2.5.0
+      *item_sort_key* is new in 2.5.0.
 
     .. note::
 
@@ -213,7 +233,7 @@ Basic Usage
         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[, **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[, **kw]]]]]]]]]]]]]]]])
 
    Serialize *obj* to a JSON formatted :class:`str`.
 
@@ -410,7 +430,7 @@ Encoders and decoders
       :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]]]]]]]]]]]])
+.. 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]]]]]]]]]]]]])
 
    Extensible JSON encoder for Python data structures.
 
@@ -465,6 +485,14 @@ Encoders and decoders
    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 *item_sort_key* is a callable (not the default), then the output of
+   dictionaries will be sorted with it. The callable will be used like this:
+   ``sorted(dct.items(), key=item_sort_key)``. This option takes precedence
+   over *sort_keys*.
+
+   .. versionchanged:: 2.5.0
+      *item_sort_key* is new in 2.5.0.
+
    If *indent* is a string, then JSON array elements and object members
    will be pretty-printed with a newline followed by that string repeated
    for each level of nesting. ``None`` (the default) selects the most compact
@@ -504,6 +532,15 @@ Encoders and decoders
    .. versionchanged:: 2.2.0
      *tuple_as_array* is new in 2.2.0.
 
+   If *bigint_as_string* is true (default: ``False``), :class:`int`` ``2**53``
+   and higher or lower than ``-2**53`` will be encoded as strings. This is to
+   avoid the rounding that happens in Javascript otherwise. Note that this
+   option loses type information, so use with extreme caution.
+
+   .. versionchanged:: 2.4.0
+     *bigint_as_string* is new in 2.4.0.
+
+
    .. method:: default(o)
 
       Implement this method in a subclass such that it returns a serializable
@@ -544,7 +581,7 @@ Encoders and decoders
       Note that :meth:`encode` has much better performance than
       :meth:`iterencode`.
 
-.. class:: JSONEncoderForHTML([skipkeys[, ensure_ascii[, check_circular[, allow_nan[, sort_keys[, indent[, separators[, encoding[, default]]]]]]]]])
+.. class:: JSONEncoderForHTML([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]]]]]]]]]]]]])
 
    Subclass of :class:`JSONEncoder` that escapes &, <, and > for embedding in HTML.
 
diff --git a/setup.py b/setup.py
index 68fb1db..aa2f515 100644
--- a/setup.py
+++ b/setup.py
@@ -7,7 +7,7 @@ from distutils.errors import CCompilerError, DistutilsExecError, \
     DistutilsPlatformError
 
 IS_PYPY = hasattr(sys, 'pypy_translation_info')
-VERSION = '2.4.0'
+VERSION = '2.5.0'
 DESCRIPTION = "Simple, fast, extensible JSON encoder/decoder for Python"
 LONG_DESCRIPTION = open('README.rst', 'r').read()
 
diff --git a/simplejson/__init__.py b/simplejson/__init__.py
index 4a5e5df..eb38b46 100644
--- a/simplejson/__init__.py
+++ b/simplejson/__init__.py
@@ -97,11 +97,11 @@ Using simplejson.tool from the shell to validate and pretty-print::
     $ echo '{ 1.2:3.4}' | python -m simplejson.tool
     Expecting property name: line 1 column 2 (char 2)
 """
-__version__ = '2.4.0'
+__version__ = '2.5.0'
 __all__ = [
     'dump', 'dumps', 'load', 'loads',
     'JSONDecoder', 'JSONDecodeError', 'JSONEncoder',
-    'OrderedDict',
+    'OrderedDict', 'simple_first',
 ]
 
 __author__ = 'Bob Ippolito <bob@redivi.com>'
@@ -139,13 +139,15 @@ _default_encoder = JSONEncoder(
     namedtuple_as_object=True,
     tuple_as_array=True,
     bigint_as_string=False,
+    item_sort_key=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, use_decimal=True,
         namedtuple_as_object=True, tuple_as_array=True,
-        bigint_as_string=False, **kw):
+        bigint_as_string=False, sort_keys=False, item_sort_key=None,
+        **kw):
     """Serialize ``obj`` as a JSON formatted stream to ``fp`` (a
     ``.write()``-supporting file-like object).
 
@@ -200,6 +202,14 @@ def dump(obj, fp, skipkeys=False, ensure_ascii=True, check_circular=True,
     lossy operation that will not round-trip correctly and should be used
     sparingly.
 
+    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. This option takes precedence over
+    *sort_keys*.
+
+    If *sort_keys* is true (default: ``False``), the output of dictionaries
+    will be sorted by item.
+
     To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the
     ``.default()`` method to serialize additional types), specify it with
     the ``cls`` kwarg.
@@ -211,7 +221,7 @@ def dump(obj, fp, skipkeys=False, ensure_ascii=True, check_circular=True,
         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 kw):
+        and not bigint_as_string and not item_sort_key and not kw):
         iterable = _default_encoder.iterencode(obj)
     else:
         if cls is None:
@@ -223,6 +233,8 @@ def dump(obj, fp, skipkeys=False, ensure_ascii=True, check_circular=True,
             namedtuple_as_object=namedtuple_as_object,
             tuple_as_array=tuple_as_array,
             bigint_as_string=bigint_as_string,
+            sort_keys=sort_keys,
+            item_sort_key=item_sort_key,
             **kw).iterencode(obj)
     # could accelerate with writelines in some versions of Python, at
     # a debuggability cost
@@ -233,8 +245,8 @@ def dump(obj, fp, skipkeys=False, ensure_ascii=True, check_circular=True,
 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, use_decimal=True,
-        namedtuple_as_object=True,
-        tuple_as_array=True, bigint_as_string=False,
+        namedtuple_as_object=True, tuple_as_array=True,
+        bigint_as_string=False, sort_keys=False, item_sort_key=None,
         **kw):
     """Serialize ``obj`` to a JSON formatted ``str``.
 
@@ -281,10 +293,18 @@ def dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True,
     If *tuple_as_array* is true (default: ``True``),
     :class:`tuple` (and subclasses) will be encoded as JSON arrays.
 
-    If bigint_as_string is true (not the default), ints 2**53 and higher
+    If *bigint_as_string* is true (not the default), ints 2**53 and higher
     or lower than -2**53 will be encoded as strings. This is to avoid the
     rounding that happens in Javascript otherwise.
 
+    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. This option takes precendence over
+    *sort_keys*.
+
+    If *sort_keys* is true (default: ``False``), the output of dictionaries
+    will be sorted by item.
+
     To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the
     ``.default()`` method to serialize additional types), specify it with
     the ``cls`` kwarg.
@@ -296,7 +316,8 @@ def dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True,
         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 kw):
+        and not bigint_as_string and not sort_keys
+        and not item_sort_key and not kw):
         return _default_encoder.encode(obj)
     if cls is None:
         cls = JSONEncoder
@@ -308,6 +329,8 @@ def dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True,
         namedtuple_as_object=namedtuple_as_object,
         tuple_as_array=tuple_as_array,
         bigint_as_string=bigint_as_string,
+        sort_keys=sort_keys,
+        item_sort_key=item_sort_key,
         **kw).encode(obj)
 
 
@@ -479,3 +502,9 @@ def _toggle_speedups(enabled):
        encoding='utf-8',
        default=None,
    )
+
+def simple_first(kv):
+    """Helper function to pass to item_sort_key to sort simple
+    elements to the top, then container elements.
+    """
+    return (isinstance(kv[1], (list, dict, tuple)), kv[0])
diff --git a/simplejson/_speedups.c b/simplejson/_speedups.c
index a0e5667..e8d6563 100644
--- a/simplejson/_speedups.c
+++ b/simplejson/_speedups.c
@@ -90,6 +90,7 @@ typedef struct _PyEncoderObject {
     int namedtuple_as_object;
     int tuple_as_array;
     int bigint_as_string;
+    PyObject *item_sort_key;
 } PyEncoderObject;
 
 static PyMemberDef encoder_members[] = {
@@ -102,6 +103,7 @@ static PyMemberDef encoder_members[] = {
     {"sort_keys", T_OBJECT, offsetof(PyEncoderObject, sort_keys), READONLY, "sort_keys"},
     {"skipkeys", T_OBJECT, offsetof(PyEncoderObject, skipkeys), READONLY, "skipkeys"},
     {"key_memo", T_OBJECT, offsetof(PyEncoderObject, key_memo), READONLY, "key_memo"},
+    {"item_sort_key", T_OBJECT, offsetof(PyEncoderObject, item_sort_key), READONLY, "item_sort_key"},
     {NULL}
 };
 
@@ -2050,6 +2052,7 @@ encoder_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
         s->sort_keys = NULL;
         s->skipkeys = NULL;
         s->key_memo = NULL;
+        s->item_sort_key = NULL;
     }
     return (PyObject *)s;
 }
@@ -2058,19 +2061,19 @@ static int
 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", 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", NULL};
 
     PyEncoderObject *s;
     PyObject *markers, *defaultfn, *encoder, *indent, *key_separator;
-    PyObject *item_separator, *sort_keys, *skipkeys, *allow_nan, *key_memo, *use_decimal, *namedtuple_as_object, *tuple_as_array, *bigint_as_string;
+    PyObject *item_separator, *sort_keys, *skipkeys, *allow_nan, *key_memo, *use_decimal, *namedtuple_as_object, *tuple_as_array, *bigint_as_string, *item_sort_key;
 
     assert(PyEncoder_Check(self));
     s = (PyEncoderObject *)self;
 
-    if (!PyArg_ParseTupleAndKeywords(args, kwds, "OOOOOOOOOOOOOO:make_encoder", kwlist,
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "OOOOOOOOOOOOOOO: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))
+        &namedtuple_as_object, &tuple_as_array, &bigint_as_string, &item_sort_key))
         return -1;
 
     s->markers = markers;
@@ -2088,6 +2091,7 @@ encoder_init(PyObject *self, PyObject *args, PyObject *kwds)
     s->namedtuple_as_object = PyObject_IsTrue(namedtuple_as_object);
     s->tuple_as_array = PyObject_IsTrue(tuple_as_array);
     s->bigint_as_string = PyObject_IsTrue(bigint_as_string);
+    s->item_sort_key = item_sort_key;
 
     Py_INCREF(s->markers);
     Py_INCREF(s->defaultfn);
@@ -2098,6 +2102,7 @@ encoder_init(PyObject *self, PyObject *args, PyObject *kwds)
     Py_INCREF(s->sort_keys);
     Py_INCREF(s->skipkeys);
     Py_INCREF(s->key_memo);
+    Py_INCREF(s->item_sort_key);
     return 0;
 }
 
@@ -2356,7 +2361,14 @@ encoder_listencode_dict(PyEncoderObject *s, PyObject *rval, PyObject *dct, Py_ss
         */
     }
 
-    if (PyObject_IsTrue(s->sort_keys)) {
+    if (PyCallable_Check(s->item_sort_key)) {
+        if (PyDict_CheckExact(dct))
+            items = PyDict_Items(dct);
+        else
+            items = PyMapping_Items(dct);
+        PyObject_CallMethod(items, "sort", "OO", Py_None, s->item_sort_key);
+    }
+    else if (PyObject_IsTrue(s->sort_keys)) {
         /* First sort the keys then replace them with (key, value) tuples. */
         Py_ssize_t i, nitems;
         if (PyDict_CheckExact(dct))
@@ -2616,6 +2628,7 @@ encoder_traverse(PyObject *self, visitproc visit, void *arg)
     Py_VISIT(s->sort_keys);
     Py_VISIT(s->skipkeys);
     Py_VISIT(s->key_memo);
+    Py_VISIT(s->item_sort_key);
     return 0;
 }
 
@@ -2635,6 +2648,7 @@ encoder_clear(PyObject *self)
     Py_CLEAR(s->sort_keys);
     Py_CLEAR(s->skipkeys);
     Py_CLEAR(s->key_memo);
+    Py_CLEAR(s->item_sort_key);
     return 0;
 }
 
diff --git a/simplejson/encoder.py b/simplejson/encoder.py
index d13d26a..05dd05c 100644
--- a/simplejson/encoder.py
+++ b/simplejson/encoder.py
@@ -107,7 +107,8 @@ class JSONEncoder(object):
             check_circular=True, allow_nan=True, sort_keys=False,
             indent=None, separators=None, encoding='utf-8', default=None,
             use_decimal=True, namedtuple_as_object=True,
-            tuple_as_array=True, bigint_as_string=False):
+            tuple_as_array=True, bigint_as_string=False,
+            item_sort_key=None):
         """Constructor for JSONEncoder, with sensible defaults.
 
         If skipkeys is false, then it is a TypeError to attempt
@@ -164,6 +165,10 @@ class JSONEncoder(object):
         If bigint_as_string is true (not the default), ints 2**53 and higher
         or lower than -2**53 will be encoded as strings. This is to avoid the
         rounding that happens in Javascript otherwise.
+
+        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.
         """
 
         self.skipkeys = skipkeys
@@ -175,6 +180,7 @@ class JSONEncoder(object):
         self.namedtuple_as_object = namedtuple_as_object
         self.tuple_as_array = tuple_as_array
         self.bigint_as_string = bigint_as_string
+        self.item_sort_key = item_sort_key
         if indent is not None and not isinstance(indent, basestring):
             indent = indent * ' '
         self.indent = indent
@@ -291,14 +297,14 @@ class JSONEncoder(object):
                 self.key_separator, self.item_separator, self.sort_keys,
                 self.skipkeys, self.allow_nan, key_memo, self.use_decimal,
                 self.namedtuple_as_object, self.tuple_as_array,
-                self.bigint_as_string)
+                self.bigint_as_string, self.item_sort_key)
         else:
             _iterencode = _make_iterencode(
                 markers, self.default, _encoder, self.indent, floatstr,
                 self.key_separator, self.item_separator, self.sort_keys,
                 self.skipkeys, _one_shot, self.use_decimal,
                 self.namedtuple_as_object, self.tuple_as_array,
-                self.bigint_as_string)
+                self.bigint_as_string, self.item_sort_key)
         try:
             return _iterencode(o, 0)
         finally:
@@ -335,7 +341,7 @@ class JSONEncoderForHTML(JSONEncoder):
 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,
+        _bigint_as_string, _item_sort_key,
         ## HACK: hand-optimized bytecode; turn globals into locals
         False=False,
         True=True,
@@ -352,6 +358,8 @@ def _make_iterencode(markers, _default, _encoder, _indent, _floatstr,
         str=str,
         tuple=tuple,
     ):
+    if _item_sort_key and not callable(_item_sort_key):
+        raise TypeError("item_sort_key must be None or callable")
 
     def _iterencode_list(lst, _current_indent_level):
         if not lst:
@@ -437,7 +445,10 @@ def _make_iterencode(markers, _default, _encoder, _indent, _floatstr,
             newline_indent = None
             item_separator = _item_separator
         first = True
-        if _sort_keys:
+        if _item_sort_key:
+            items = dct.items()
+            items.sort(key=_item_sort_key)
+        elif _sort_keys:
             items = dct.items()
             items.sort(key=lambda kv: kv[0])
         else:
diff --git a/simplejson/tests/test_item_sort_key.py b/simplejson/tests/test_item_sort_key.py
new file mode 100644
index 0000000..83bea1e
--- /dev/null
+++ b/simplejson/tests/test_item_sort_key.py
@@ -0,0 +1,20 @@
+from unittest import TestCase
+
+import simplejson as json
+from operator import itemgetter
+
+class TestItemSortKey(TestCase):
+    def test_simple_first(self):
+        a = {'a': 1, 'c': 5, 'jack': 'jill', 'pick': 'axe', 'array': [1, 5, 6, 9], 'tuple': (83, 12, 3), 'crate': 'dog', 'zeak': 'oh'}
+        self.assertEquals(
+            '{"a": 1, "c": 5, "crate": "dog", "jack": "jill", "pick": "axe", "zeak": "oh", "array": [1, 5, 6, 9], "tuple": [83, 12, 3]}',
+            json.dumps(a, item_sort_key=json.simple_first))
+
+    def test_case(self):
+        a = {'a': 1, 'c': 5, 'Jack': 'jill', 'pick': 'axe', 'Array': [1, 5, 6, 9], 'tuple': (83, 12, 3), 'crate': 'dog', 'zeak': 'oh'}
+        self.assertEquals(
+            '{"Array": [1, 5, 6, 9], "Jack": "jill", "a": 1, "c": 5, "crate": "dog", "pick": "axe", "tuple": [83, 12, 3], "zeak": "oh"}',
+            json.dumps(a, item_sort_key=itemgetter(0)))
+        self.assertEquals(
+            '{"a": 1, "Array": [1, 5, 6, 9], "c": 5, "crate": "dog", "Jack": "jill", "pick": "axe", "tuple": [83, 12, 3], "zeak": "oh"}',
+            json.dumps(a, item_sort_key=lambda kv: kv[0].lower()))