[Python-Dev] Re: PEP 218 (sets); moving set.py to Lib

Guido van Rossum guido@python.org
Wed, 21 Aug 2002 01:14:27 -0400

A few transformations down the road, here's a 4-line powerset() generator:

def powerset(base):
    pairs = [(2**i, x) for i, x in enumerate(base)]
    for n in xrange(2**len(pairs)):
        yield [x for m, x in pairs if m&n]

--Guido van Rossum (home page: http://www.python.org/~guido/)