These negative votes surprise me. Given that it's clear that a generic strict-mode zip is non-trivial to write, and that there is significant demand for it, are people saying "+0 Python would not be a better programming environment if itertools.zip_strict() were adopted," and "-1 Python would be a worse programming environment if zip.strict() were adopted"? I can see why folks would say the latter about zip.strict(), but even though I really dislike the mode switches, I'm still positive about adding them if one of them ranks highest among those who care. I'm not going to give them negative votes, they don't make Python worse. I don't mind hyperbole ("I'm +1000 on this feature!" or "-10 on the worst proposal I've seen since <potentially controversial example removed>!") But I would like it if "0" meant "indifferent", "+1" meant "no-brainer, add it", and "-1" meant "no-brainer, just don't". FWIW, +1 itertools.zip_strict(*iterables) +0.5 zip(*iterables, mode) # mode is 3-way, default "shortest" +0.4 zip(*iterables, strict) # strict is boolean, default False +0 zip.strict(*iterables)