from itertools import chain, izip_longest def roundrobin(*iterables): sentinel = object() return (x for x in chain(*izip_longest(fillvalue=sentinel, *iterables)) if x is not sentinel)
from itertools import chain, izip_longest def roundrobin(*iterables): sentinel = object() return (x for x in chain(*izip_longest(fillvalue=sentinel, *iterables)) if x is not sentinel)