subgroups and permutations in python

script.py

Set = ['A', 'B', 'C', 'D']
Subsets = []
n = len(Set)

for i in xrange(pow(2, n)): 
    binaryDigits = (bin(i)[2:]).zfill(n)
    subset = ''
    j = 0
    for digit in binaryDigits:
        if(digit == '1'):
            subset += Set[j]
        j += 1
    Subsets.append(subset)

print 'distinct subgroups in set', Set, ':'
print Subsets

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import itertools
print 'permutations of set', Set, ':'
print list(itertools.permutations(Set))