def zip_with(fn, *colls):
return itertools.starmap(fn, itertools.izip(*colls))<EOL>
Return the result of the function applied on the zip of the collections

    :param fn: a function
    :param colls: collections
    :returns: an iterator

    >>> list(zip_with(lambda x, y: x-y, [10, 20, 30], [42, 19, 43]))
    [-32, 1, -13]