Power Set – algorithmic and fast

class Solution: 
    # @param A : list of integers 
    # @return a list of list of integers 
    def subsets(self, A):     
        if len(A) == 0:         
            return [[]]     
        h, t = A[0], A[1:]     
        subsets_excluding_h = self.subsets(t)     
        subsets_including_h = [sorted([h] + ss) for ss in subsets_excluding_h]     
    return sorted(subsets_including_h + subsets_excluding_h)

1. Recursive method to find all subsets of a given list
2. Python 3
3. It's quite fast.