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Groups > comp.lang.python > #66241

Re: A curious bit of code...

From Neil Cerutti <neilc@norwich.edu>
Subject Re: A curious bit of code...
Date 2014-02-13 21:01 +0000
Organization Norwich University
References <4cc09129-43ee-4205-a24c-03f92b594abc@googlegroups.com> <CAKJDb-OoN2K4--AseaFkuXv3-4vr+a3TPQc7omSrsHVYKcbBrw@mail.gmail.com>
Newsgroups comp.lang.python
Message-ID <mailman.6882.1392325299.18130.python-list@python.org> (permalink)

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On 2014-02-13, Zachary Ware <zachary.ware+pylist@gmail.com> wrote:
> In a fit of curiosity, I did some timings:
>
> 'and'ed indexing:
>
> C:\tmp>py -m timeit -s "key = '<test>'" "key[0] == '<' and key[-1] == '>'"
> 1000000 loops, best of 3: 0.35 usec per loop
>
> C:\tmp>py -m timeit -s "key = '<test'" "key[0] == '<' and key[-1] == '>'"
> 1000000 loops, best of 3: 0.398 usec per loop
>
> C:\tmp>py -m timeit -s "key = 'test>'" "key[0] == '<' and key[-1] == '>'"
> 1000000 loops, best of 3: 0.188 usec per loop
>
> C:\tmp>py -m timeit -s "key = 'test'" "key[0] == '<' and key[-1] == '>'"
> 10000000 loops, best of 3: 0.211 usec per loop
>
> C:\tmp>py -m timeit -s "key = ''" "key[0] == '<' and key[-1] == '>'"
> Traceback (most recent call last):
>   File "P:\Python34\lib\timeit.py", line 292, in main
>     x = t.timeit(number)
>   File "P:\Python34\lib\timeit.py", line 178, in timeit
>     timing = self.inner(it, self.timer)
>   File "<timeit-src>", line 6, in inner
>     key[0] == '<' and key[-1] == '>'
> IndexError: string index out of range

The corrected version

key and key[0] == '<' and key[-1] == '>'

probably still wins the Pretty Unimportant Olympics.

-- 
Neil Cerutti

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Thread

A curious bit of code... forman.simon@gmail.com - 2014-02-13 10:37 -0800
  Re: A curious bit of code... Roy Smith <roy@panix.com> - 2014-02-13 13:45 -0500
  Re: A curious bit of code... Ethan Furman <ethan@stoneleaf.us> - 2014-02-13 10:45 -0800
  Re: A curious bit of code... Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-02-13 19:09 +0000
  Re: A curious bit of code... Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2014-02-13 20:05 +0100
  Re: A curious bit of code... Neil Cerutti <neilc@norwich.edu> - 2014-02-13 19:17 +0000
  Re: A curious bit of code... Ethan Furman <ethan@stoneleaf.us> - 2014-02-13 11:20 -0800
    Re: A curious bit of code... Roy Smith <roy@panix.com> - 2014-02-13 14:28 -0500
  Re: A curious bit of code... Ethan Furman <ethan@stoneleaf.us> - 2014-02-13 11:25 -0800
  Re: A curious bit of code... Neil Cerutti <neilc@norwich.edu> - 2014-02-13 19:25 +0000
  Re: A curious bit of code... Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-02-13 19:32 +0000
  Re: A curious bit of code... Peter Otten <__peter__@web.de> - 2014-02-13 20:43 +0100
    Re: A curious bit of code... Marko Rauhamaa <marko@pacujo.net> - 2014-02-13 21:56 +0200
  Re: A curious bit of code... Ethan Furman <ethan@stoneleaf.us> - 2014-02-13 11:23 -0800
  Re: A curious bit of code... Neil Cerutti <neilc@norwich.edu> - 2014-02-13 19:51 +0000
  Re: A curious bit of code... Ethan Furman <ethan@stoneleaf.us> - 2014-02-13 11:59 -0800
  Re: A curious bit of code... Zachary Ware <zachary.ware+pylist@gmail.com> - 2014-02-13 13:59 -0600
  Re: A curious bit of code... Chris Angelico <rosuav@gmail.com> - 2014-02-14 07:29 +1100
  Re: A curious bit of code... Tim Chase <python.list@tim.thechases.com> - 2014-02-13 14:39 -0600
  Re: A curious bit of code... Emile van Sebille <emile@fenx.com> - 2014-02-13 12:55 -0800
    Re: A curious bit of code... Roy Smith <roy@panix.com> - 2014-02-13 16:24 -0500
      Re: A curious bit of code... Ethan Furman <ethan@stoneleaf.us> - 2014-02-13 16:23 -0800
  Re: A curious bit of code... Chris Angelico <rosuav@gmail.com> - 2014-02-14 08:01 +1100
  Re: A curious bit of code... Neil Cerutti <neilc@norwich.edu> - 2014-02-13 21:01 +0000
  Re: A curious bit of code... Peter Otten <__peter__@web.de> - 2014-02-13 22:06 +0100
  Re: A curious bit of code... Chris Angelico <rosuav@gmail.com> - 2014-02-14 08:10 +1100
  Re: A curious bit of code... Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-02-13 21:14 +0000
  Re: A curious bit of code... Zachary Ware <zachary.ware+pylist@gmail.com> - 2014-02-13 15:20 -0600
  Re: A curious bit of code... Zachary Ware <zachary.ware+pylist@gmail.com> - 2014-02-13 15:19 -0600
  Re: A curious bit of code... Emile van Sebille <emile@fenx.com> - 2014-02-13 13:23 -0800
  Re: A curious bit of code... Chris Angelico <rosuav@gmail.com> - 2014-02-14 08:31 +1100
    Re: A curious bit of code... Roy Smith <roy@panix.com> - 2014-02-13 16:38 -0500
  Re: A curious bit of code... Zachary Ware <zachary.ware+pylist@gmail.com> - 2014-02-13 15:47 -0600
  Re: A curious bit of code... Serhiy Storchaka <storchaka@gmail.com> - 2014-02-13 23:49 +0200
    Re: A curious bit of code... Roy Smith <roy@panix.com> - 2014-02-13 16:51 -0500
  Re: A curious bit of code... Ethan Furman <ethan@stoneleaf.us> - 2014-02-13 13:33 -0800
  Re: A curious bit of code... Chris Angelico <rosuav@gmail.com> - 2014-02-14 09:13 +1100
  Re: A curious bit of code... Ethan Furman <ethan@stoneleaf.us> - 2014-02-13 14:26 -0800
  Re: A curious bit of code... Terry Reedy <tjreedy@udel.edu> - 2014-02-13 19:29 -0500
  Re: A curious bit of code... forman.simon@gmail.com - 2014-02-13 18:45 -0800
    Re: A curious bit of code... Ned Batchelder <ned@nedbatchelder.com> - 2014-02-13 22:26 -0500
      Re: A curious bit of code... forman.simon@gmail.com - 2014-02-14 12:04 -0800
        Re: A curious bit of code... Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-02-14 21:01 +0000
  Re: A curious bit of code... Dave Angel <davea@davea.name> - 2014-02-14 07:19 -0500
    Re: A curious bit of code... Roy Smith <roy@panix.com> - 2014-02-14 09:06 -0500

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