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Re: Bizarre behavior of the 'find' method of strings

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Date Wed, 10 Aug 2011 20:49:49 -0700
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Subject Re: Bizarre behavior of the 'find' method of strings
From Chris Rebert <clp2@rebertia.com>
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On Wed, Aug 10, 2011 at 7:56 PM, Steven D'Aprano
<steve+comp.lang.python@pearwood.info> wrote:
> On Thu, 11 Aug 2011 11:24 am Jim wrote:
>
>> Greetings, folks,
>>
>> I am using python 2.7.2. Here is something I got:
>>>>> a = 'popular'
>>>>> i = a.find('o')
>>>>> j = a.find('a')
>>>>> a[i:j]
>> 'opul'
>>
>> Well, I expected a[i:j] to be 'opula', and can't think of any reason why
>> this is not happening. So, can anybody help me out about this? Thank you
>> very much.
<snip>
> "Why does slicing not work the way I expect?"
>
> Answer: because Python uses half-open slices, where the end parameter is not
> included. The reason for that is that experience with other languages shows
> that it leads to fewer "off-by-one" errors.
>
> See also:
>
> http://mail.python.org/pipermail/tutor/2010-December/080592.html
> http://en.wikipedia.org/wiki/Off-by-one_error

And further:
http://www.cs.utexas.edu/users/EWD/transcriptions/EWD08xx/EWD831.html

Cheers,
Chris

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Thread

Bizarre behavior of the 'find' method of strings Jim <jianbao.tao@gmail.com> - 2011-08-10 18:24 -0700
  Re: Bizarre behavior of the 'find' method of strings MRAB <python@mrabarnett.plus.com> - 2011-08-11 02:48 +0100
  Re: Bizarre behavior of the 'find' method of strings Chris Angelico <rosuav@gmail.com> - 2011-08-11 03:14 +0100
  Re: Bizarre behavior of the 'find' method of strings Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-08-11 12:56 +1000
    Re: Bizarre behavior of the 'find' method of strings Chris Rebert <clp2@rebertia.com> - 2011-08-10 20:49 -0700
      Re: Bizarre behavior of the 'find' method of strings Jim <jianbao.tao@gmail.com> - 2011-08-10 21:29 -0700
      Re: Bizarre behavior of the 'find' method of strings Jim <jianbao.tao@gmail.com> - 2011-08-10 21:29 -0700

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