flatten.py

#!/usr/bin/env python
# encoding: utf-8

import json


def flatten(json_str):
    dic = json.loads(json_str)
    flattened_dic = _flatten(dic)
    return json.dumps(flattened_dic)


def _flatten(dic):
    result = {}
    for k, v in dic.iteritems():
        if not isinstance(v, dict):
            result[k] = v
        else:
            for kk, vv in _flatten(v).iteritems():
                result['%s.%s' % (k, kk)] = vv

    return result


print flatten(json.dumps({
    'a': 1,
    'b': 2,
    'c': {
        'c1': 'test',
        'c2': [1, 2, 3]
    }
}))

# {"a": 1, "b": 2, "c.c2": [1, 2, 3], "c.c1": "test"}