The pairwise recipe function in itertools demonstrates just that (using tee instead of multiplying the iterator): http://docs.python.org/2/library/itertools.ht

The pairwise recipe function in itertools demonstrates just that (using tee instead of multiplying the iterator): http://docs.python.org/2/library/itertools.html http://docs.python.org/2/library/itertools.html def pairwise(iterable): "s -> (s0,s1), (s1,s2), (s2, s3), ..." a, b = tee(iterable) next(b, None) return izip(a, b)