json serialize a dictionary with tuples as key

Question

Is there a way in Python to serialize a dictionary that is using a tuple as key:

a={(1,2):\'a\'}

simply using json.dumps(a), produces:

Answer 1

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]}]'