Generates all possible combinations of values for dictionary (useful for tests)

combinations_dict.py

from itertools import combinations

def combinations_dict(data):
    """
    Generates all possible combinations of values for dictionary.

    At the entrance you can pass either dictionary or list of tuples.

    Examples::

        combinations_dict({
            'a': 'A', 'b': 'B', 'c': 'C'
        })
        >> {'a': 'A'}
        >> {'c': 'C'}
        >> {'b': 'B'}
        >> {'a': 'A', 'b': 'B'}
        >> {'a': 'A', 'c': 'C'}
        >> {'b': 'B', 'c': 'C'}
        >> {'a': 'A', 'b': 'B', 'c': 'C'}

        combinations_dict([
            ('a', 'A'), ('b', 'B_1'), ('b', 'B_2'),
        ])
        >> {'a': 'A'}
        >> {'b': 'B_1'}
        >> {'b': 'B_2'}
        >> {'a': 'A', 'b': 'B_1'}
        >> {'a': 'A', 'b': 'B_2'}


    :param dict or list of tuples data:
    :return dict:
    """
    if isinstance(data, dict):
        _items = lambda: data.iteritems()
        keys_count = len(data)
    elif isinstance(data, list):
        _items = lambda: data
        keys_count = len(set(x[0] for x in _items()))
    else:
        raise ValueError

    for count in xrange(1, keys_count+1):
        for p in combinations(_items(), count):
            rt = dict(p)
            if len(rt) == count:
                yield rt