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

[Georg Brandl]

Giovanni Bajo wrote:
> 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()
>     ...

enumerate() starts at 0, count(1) at 1, so you'd have to do a

   lineno += 1

in the body too.

Whether

   for lineno, ts, line in zip(count(1), timestamp(), sys.stdin):

is more complicated than

   for lineno, line in enumerate(sys.stdin):
       ts = time.time()
       lineno += 1

is a stylistic question.

(However, enumerate() could grow a second argument specifying the
starting index).

Georg