["python","json","tuples"]
JSON serialize a dictionary with tuples as key

Is there a way in Python to serialize a dictionary that is using a tuple as key? e.g. a = {(1, 2): 'a'} simply using json.dumps(a) raises this error: Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/usr/lib/python2.6/json/__init__.py", line 230, in dumps return _default_encoder.encode(obj) File "/usr/lib/python2.6/json/encoder.py", line 367, in encode chunks = list(self.iterencode(o)) File "/usr/lib/python2.6/json/encoder.py", line 309, in _iterencode for chunk in self._iterencode_dict(o, markers): File "/usr/lib/python2.6/json/encoder.py", line 268, in _iterencode_dict raise TypeError("key {0!r} is not a string".format(key)) TypeError: key (1, 2) is not a string
You can't serialize that as json, json has a much less flexible idea about what counts as a dict key than python. You could transform the mapping into a sequence of key, value pairs, something like this: import json def remap_keys(mapping): return [{'key':k, 'value': v} for k, v in mapping.iteritems()] ... json.dumps(remap_keys({(1, 2): 'foo'})) >>> '[{"value": "foo", "key": [1, 2]}]'