[Python-3000] have zip() raise exception for sequences of different lengths

Giovanni Bajo rasky at develer.com
Tue Sep 5 15:17:49 CEST 2006

Raymond Hettinger wrote:

> It's a PITA because it precludes all of the use cases whether the
> inputs ARE intentionally of different length (like when one argument
> supplys an infinite iterator):
>    for lineno, ts, line in zip(count(1), timestamp(), sys.stdin):
>        print 'Line %d, Time %s:  %s)' % (lineno, ts, line)

which is a much more complicated way of writing:

for lineno, line in enumerate(sys.stdin):
    ts = time.time()

[assuming your "timestamp()" is what I think it is, never heard of it

I double-checked my own uses of zip() and they seem to follow the trend of
those in Python stdlib: most of the cases are really programming errors if
the two sequences do not match in length. I reckon the usage of infinite
iterators is generally much less common.
Giovanni Bajo

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