Python recursive function to display all subsets of given set

def subs(l):
    if l == []:
        return [[]]

    x = subs(l[1:])

    return x + [[l[0]] + y for y in x]

Results:

>>> print (subs([1, 2, 3]))
[[], [3], [2], [2, 3], [1], [1, 3], [1, 2], [1, 2, 3]]