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Re: Iterators membership testing

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Date Sun, 9 Aug 2015 08:09:51 -0500
From Tim Chase <python.list@tim.thechases.com>
To "python-list@python.org" <python-list@python.org>
Subject Re: Iterators membership testing
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On 2015-08-09 19:24, Chris Angelico wrote:
> That's exactly right. The only way for the interpreter to handle
> 'in' on an iterator is something like this:
> 
> def contains(iter, obj):
>     for val in iter:
>         if val == obj: return True
>     return False

Which can nicely be written as

  any(i == obj for obj in iter)

The addition of any/all initially struck me as a "why?! this is so
easy to write in-line" moment, only to find myself using them all()
the time. :-) The code-intention becomes so much clearer.  Even
back-ported them to 2.4 code that I maintain.

-tkc

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Thread

Iterators membership testing Pierre Quentel <pierre.quentel@gmail.com> - 2015-08-09 02:06 -0700
  Re: Iterators membership testing Chris Angelico <rosuav@gmail.com> - 2015-08-09 19:24 +1000
    Re: Iterators membership testing Pierre Quentel <pierre.quentel@gmail.com> - 2015-08-09 02:55 -0700
      Re: Iterators membership testing Chris Angelico <rosuav@gmail.com> - 2015-08-09 20:13 +1000
        Re: Iterators membership testing Pierre Quentel <pierre.quentel@gmail.com> - 2015-08-09 04:00 -0700
          Re: Iterators membership testing Chris Angelico <rosuav@gmail.com> - 2015-08-09 21:10 +1000
      Re: Iterators membership testing Laura Creighton <lac@openend.se> - 2015-08-09 13:30 +0200
      Re: Iterators membership testing Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-08-09 14:49 +0100
  Re: Iterators membership testing Chris Angelico <rosuav@gmail.com> - 2015-08-09 23:11 +1000
  Re: Iterators membership testing Tim Chase <python.list@tim.thechases.com> - 2015-08-09 08:09 -0500
  Re: Iterators membership testing Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-08-09 14:45 +0100
  Re: Iterators membership testing Tim Chase <tim@thechases.com> - 2015-08-09 08:09 -0500

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