index() of sequence type?
gagsl-py2 at yahoo.com.ar
Thu Feb 7 22:57:07 CET 2008
En Thu, 07 Feb 2008 11:31:44 -0200, Diez B. Roggisch <deets at nospam.web.de>
>> I see list has index member, but is there an index function that applies
>> to any sequence type?
>> If not, shouldn't there be?
> Looks like an oversight to me as well, yes. The only "difficult"
> implementation would be the one for xrange, because you can't search but
> must compute the result - but that should be trivial.
xrange is iterable, but not a sequence. Tuples are worse: they implement
__contains__ but not index. So you can say:
py> 2 in (1,2,4,8)
Given that to implement __contains__ it has to scan the values the same
way as index would do, it's like a tuple saying: "I know where that item
is, and you know that I know that, but I won't tell you!" - rather
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