If I am understanding what you're looking for, you can use itertools.product() over the powersets of the inputs (there is a recipe for powerset() in the docs). The map() function can be used to apply powerset to each of the inputs.
from itertools import product, combinations, chain
from pprint import pprint
def powerset(iterable):
"powerset([1,2,3]) --> () (1,) (2,) (3,) (1,2) (1,3) (2,3) (1,2,3)"
s = list(iterable)
return chain.from_iterable(combinations(s, r) for r in range(len(s)+1))
names = ['a', 'b', 'c']
a = ["x", "y"]
b = ["q", "w", "c"]
c = ["i", "o", "p"]
result = []
for values in product(*map(powerset, [a, b, c])):
result.append(dict(zip(names, values)))
pprint(result)
Here is how it works:
First, it builds the powersets:
>>> list(powerset(["x", "y"]))
[(), ('x',), ('y',), ('x', 'y')]
>>>
>>> list(powerset(["x", "y"]))
[(), ('x',), ('y',), ('x', 'y')]
>>> list(powerset(["q", "w", "c"]))
[(), ('q',), ('w',), ('c',), ('q', 'w'), ('q', 'c'),
('w', 'c'), ('q', 'w', 'c')]
>>> list(powerset(["i", "o", "p"]))
[(), ('i',), ('o',), ('p',), ('i', 'o'), ('i', 'p'),
('o', 'p'), ('i', 'o', 'p')]
Next product() pulls one element from each powerset:
>>> for values in product(*map(powerset, [a, b, c])):
print(values)
((), (), ())
((), (), ('i',))
((), (), ('o',))
((), (), ('p',))
((), (), ('i', 'o'))
((), (), ('i', 'p'))
((), (), ('o', 'p'))
((), (), ('i', 'o', 'p'))
((), ('q',), ())
((), ('q',), ('i',))
((), ('q',), ('o',))
((), ('q',), ('p',))
((), ('q',), ('i', 'o'))
((), ('q',), ('i', 'p'))
((), ('q',), ('o', 'p'))
((), ('q',), ('i', 'o', 'p'))
Lastly, we zip() together the above results with the variable names to make a dict():
# What zip does
>>> list(zip(['a', 'b', 'c'], ((), ('q',), ('i', 'o', 'p'))))
[('a', ()), ('b', ('q',)), ('c', ('i', 'o', 'p'))]
# What dict does with the zip:
>>> dict(zip(['a', 'b', 'c'], ((), ('q',), ('i', 'o', 'p'))))
{'b': ('q',), 'c': ('i', 'o', 'p'), 'a': ()}
