itertools.ilen?
Michael Peuser
mpeuser at web.de
Thu Aug 7 04:35:59 EDT 2003
"Terry Reedy" <tjreedy at udel.edu> schrieb im Newsbeitrag
news:tpKdnUQ75tjOZKyiU-KYuQ at comcast.com...
>
> "Jeremy Fincher" <fincher.*@osu.edu> wrote in message
> news:bgsqj5$228$1 at news.cis.ohio-state.edu...
> > Sometimes I find myself simply wanting the length of an iterator.
>
> An iterator is a function/method that traverses (or possibly
> generates) a seqeuence. The sequence has a length (actual or
> potential) but the iterator does not.
>
Very well explained. There are lots of usefull generators with unlimited
sequences.
- random generators
- def achilles():
while 1
:N=1.
yield N
n=n/2
- def schoenberg():
cycle=range(12)
while 1:
shuffle(cycle)
for i in cycle:
yield i
There is no way to determined, whether such generartors will come to an
end - The Halting Problem for Turing Machines ;-)
Thus there will never be a safe len(iterator).
Kindly
Michael
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