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Re: Strange range

From Marko Rauhamaa <marko@pacujo.net>
Newsgroups comp.lang.python
Subject Re: Strange range
Date 2016-04-02 23:44 +0300
Organization A noiseless patient Spider
Message-ID <87zitbpwpr.fsf@elektro.pacujo.net> (permalink)
References (1 earlier) <56fe76f2$0$22141$c3e8da3$5496439d@news.astraweb.com> <ndlvrt$1hlp$1@gioia.aioe.org> <mailman.311.1459521083.28225.python-list@python.org> <87lh4xjt37.fsf@elektro.pacujo.net> <1671ea2b-09ff-4745-a6e7-d2c57864cba3@googlegroups.com>

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Ned Batchelder <ned@nedbatchelder.com>:

> This analogy illuminates an important point: a single iterable can have
> a number of active iterators working over it at once, just as a book can
> have a number of bookmarks in it at once.
>
>     nums = [1, 2, 3]
>     for i in nums:
>         for j in nums:
>             print i, j
>
> This prints all the pairs of numbers, because the iterator in the first
> loop is independent of the iterator(s) in the second loop, even though
> they are iterating over the same iterator (the nums list).  Without the
> extra indirection of iterators over iterables, this code would get
> tangled up.

I don't have a problem with a list being a "reiterable." I only was
surprised about range(), which I had thought to be a plain,
down-to-earth iterator. There's barely any other practical use for a
range, I believe.


Marko

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Thread

Strange range Marko Rauhamaa <marko@pacujo.net> - 2016-04-01 16:15 +0300
  Re: Strange range Chris Angelico <rosuav@gmail.com> - 2016-04-02 00:24 +1100
  Re: Strange range Steven D'Aprano <steve@pearwood.info> - 2016-04-02 00:26 +1100
    Re: Strange range Marko Rauhamaa <marko@pacujo.net> - 2016-04-01 17:12 +0300
      Re: Strange range Random832 <random832@fastmail.com> - 2016-04-01 10:39 -0400
    Re: Strange range Fabien <fabien.maussion@gmail.com> - 2016-04-01 16:16 +0200
      Re: Strange range Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-04-01 17:28 +0300
      Re: Strange range Chris Angelico <rosuav@gmail.com> - 2016-04-02 01:31 +1100
        Re: Strange range Marko Rauhamaa <marko@pacujo.net> - 2016-04-01 17:34 +0300
          Re: Strange range Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-04-01 17:44 +0300
          Re: Strange range Chris Angelico <rosuav@gmail.com> - 2016-04-02 01:45 +1100
            Re: Strange range Marko Rauhamaa <marko@pacujo.net> - 2016-04-01 18:43 +0300
          Re: Strange range Erik <python@lucidity.plus.com> - 2016-04-01 20:58 +0100
            Re: Strange range Marko Rauhamaa <marko@pacujo.net> - 2016-04-01 23:14 +0300
              Re: Strange range Rob Gaddi <rgaddi@highlandtechnology.invalid> - 2016-04-01 20:21 +0000
                Re: Strange range Marko Rauhamaa <marko@pacujo.net> - 2016-04-01 23:44 +0300
              Re: Strange range Steven D'Aprano <steve@pearwood.info> - 2016-04-02 21:09 +1100
                Re: Strange range Marko Rauhamaa <marko@pacujo.net> - 2016-04-02 13:48 +0300
          Re: Strange range Ned Batchelder <ned@nedbatchelder.com> - 2016-04-02 12:47 -0700
            Re: Strange range Marko Rauhamaa <marko@pacujo.net> - 2016-04-02 23:44 +0300
              Re: Strange range Chris Angelico <rosuav@gmail.com> - 2016-04-03 07:05 +1000
                Re: Strange range Marko Rauhamaa <marko@pacujo.net> - 2016-04-03 00:40 +0300
                Re: Strange range Ned Batchelder <ned@nedbatchelder.com> - 2016-04-02 14:50 -0700
                Re: Strange range Stephen Hansen <me+python@ixokai.io> - 2016-04-02 23:43 -0700
                Re: Strange range Marko Rauhamaa <marko@pacujo.net> - 2016-04-03 09:58 +0300
                Re: Strange range Chris Angelico <rosuav@gmail.com> - 2016-04-03 17:10 +1000
                Re: Strange range Ethan Furman <ethan@stoneleaf.us> - 2016-04-03 09:28 -0700
                Re: Strange range Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-04-04 13:21 +0100
                Re: Strange range Chris Angelico <rosuav@gmail.com> - 2016-04-03 17:08 +1000
              Re: Strange range Steven D'Aprano <steve@pearwood.info> - 2016-04-03 14:43 +1000
                Re: Strange range Random832 <random832@fastmail.com> - 2016-04-03 01:20 -0400
                Re: Strange range Steven D'Aprano <steve@pearwood.info> - 2016-04-03 15:28 +1000
      Re: Strange range Marko Rauhamaa <marko@pacujo.net> - 2016-04-01 17:32 +0300
  Re: Strange range Random832 <random832@fastmail.com> - 2016-04-01 10:42 -0400
  Re: Strange range Chris Angelico <rosuav@gmail.com> - 2016-04-02 01:50 +1100
  Re: Strange range Ian Kelly <ian.g.kelly@gmail.com> - 2016-04-01 08:52 -0600

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