IterTools .combinations() to create all possible subsets, of all sizes, of a larger set

combinations.py

# create all combinations of all subsets, excluding "groups" of single numbers
# e.g. for below would create the original nums, groups of 4, groups of 3, groups of 2
import itertools
nums = [3,5,9,1,3]
groups = []
for group_size in range(2, len(nums) + 1):
    for subset in itertools.combinations(nums, group_size):
        groups.append(subset)