for(each) element aliasing
Reinhold Birkenfeld
reinhold-birkenfeld-nospam at wolke7.net
Mon Nov 22 13:34:01 EST 2004
Matija Papec wrote:
> X-Ftn-To: Jp Calderone
>
> Jp Calderone <exarkun at divmod.com> wrote:
>>> -------
>>> 2 4 6
>>
>> No. Integers in Python are immutable. For lists of other things, mutation in-place (similar to the above example) is possible, but for integers and other immutable types, it is not. You may be interested in list comprehensions, though:
>>
>> arr = range(1, 4)
>> arr[:] = [a * 2 for a in arr]
>> print arr
>
> I guess this works like "map" but "for" is more idimatic.
Yes. List comprehensions are elegant (and fast) expressions you would
otherwise construct with map() and filter().
Reinhold
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