def izip_longest(*args, **kwds):
    # izip_longest('ABCD', 'xy', fillvalue='-') --> Ax By C- D-
    fillvalue = kwds.get('fillvalue')
    def sentinel(counter = ([fillvalue]*(len(args)-1)).pop):
        yield counter()         # yields the fillvalue, or raises IndexError
    fillers = itertools.repeat(fillvalue)
    iters = [itertools.chain(it, sentinel(), fillers) for it in args]
    try:
        for tup in itertools.izip(*iters):
            yield tup
    except __HOLE__:
        pass
dataset/ETHPy150Open CountZer0/PipelineConstructionSet/python/maya/site-packages/pymel-1.0.3/pymel/util/arguments.py/izip_longest