Convert properties file style dict to JSON style

dedot.py

# -*- coding: utf-8 -*-


def dedot(doc):
    '''Convert proprty file style dict to JSON style dict:

        {
            'foo.bar' : 1,
            'foo.baz.0' : 'a',
            'foo.baz.1' : 'b',
        }

        to

        {
            'foo' : {
                'bar' : 1
                'baz' : ['a','b']
            },
        }
     '''

    out = {}

    for k in sorted(doc.keys()):
        parent = None
        current = out
        prev_key = None

        for key in k.split('.'):
            try:
                int_key = int(key)
                if len(current) > 0 and not isinstance(current, list):
                    raise Exception('Wrong input dict. Expecting list.')
                elif isinstance(current, dict):
                    parent[prev_key] = []
                    current = parent[prev_key]
                if int_key >= len(current):
                    current.insert(int_key, {})
                prev_key = int_key
                parent = current
                current = current[int_key]
            except ValueError:
                if key not in current:
                    current[key] = {}
                parent = current
                current = current[key]
                prev_key = key

        parent[prev_key] = doc[k]

    return out

Makefile

test:
	PYTHONPATH=. python test_dedot.py

test_dedot.py

# -*- coding: utf-8 -*-

from dedot import dedot

def test_dedot():
    doted_dict = {
        'foo.bar' : 1,
        'foo.baz.0' : 'a',
        'foo.baz.1' : 'b',
        'spam.0.eggs' : 10,
        'spam.0.bread' : 20,
    }

    json_dict = dedot(doted_dict)

    assert json_dict == {
        'foo' : {
            'bar' : 1,
            'baz' : ['a', 'b'],
        },
        'spam' : [
            {
                'eggs' : 10,
                'bread' : 20,
            }
        ]
    }


if __name__ == '__main__':
    test_dedot()