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Re: Good use for itertools.dropwhile and itertools.takewhile

From Neil Cerutti <neilc@norwich.edu>
Newsgroups comp.lang.python
Subject Re: Good use for itertools.dropwhile and itertools.takewhile
Date 2012-12-04 14:23 +0000
Organization Norwich University
Message-ID <ai6fb6Fk3vkU7@mid.individual.net> (permalink)
References <b80f3ab3-ef81-4806-86db-efd5800d4bb3@googlegroups.com>

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On 2012-12-04, Nick Mellor <thebalancepro@gmail.com> wrote:
> I have a file full of things like this:
>
> "CAPSICUM RED fresh from Queensland"
>
> Product names (all caps, at start of string) and descriptions
> (mixed case, to end of string) all muddled up in the same
> field. And I need to split them into two fields. Note that if
> the text had said:
>
> "CAPSICUM RED fresh from QLD"
>
> I would want QLD in the description, not shunted forwards and
> put in the product name. So (uncontrived) list comprehensions
> and regex's are out.
>
> I want to split the above into:
>
> ("CAPSICUM RED", "fresh from QLD")
>
> Enter dropwhile and takewhile. 6 lines later:
>
> from itertools import takewhile, dropwhile
> def split_product_itertools(s):
>     words = s.split()
>     allcaps = lambda word: word == word.upper()
>     product, description = takewhile(allcaps, words), dropwhile(allcaps, words)
>     return " ".join(product), " ".join(description)
>
> When I tried to refactor this code to use while or for loops, I
> couldn't find any way that felt shorter or more pythonic:

I'm really tempted to import re, and that means takewhile and
dropwhile need to stay. ;)

But seriously, this is a quick implementation of my first thought.

description = s.lstrip(string.ascii_uppercase + ' ')
product = s[:-len(description)-1]

-- 
Neil Cerutti

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Good use for itertools.dropwhile and itertools.takewhile Nick Mellor <thebalancepro@gmail.com> - 2012-12-04 05:57 -0800
  Re: Good use for itertools.dropwhile and itertools.takewhile Neil Cerutti <neilc@norwich.edu> - 2012-12-04 14:23 +0000
    Re: Good use for itertools.dropwhile and itertools.takewhile Nick Mellor <thebalancepro@gmail.com> - 2012-12-04 06:47 -0800
      Re: Good use for itertools.dropwhile and itertools.takewhile Neil Cerutti <neilc@norwich.edu> - 2012-12-04 15:17 +0000
  Re: Good use for itertools.dropwhile and itertools.takewhile Vlastimil Brom <vlastimil.brom@gmail.com> - 2012-12-04 15:31 +0100
    Re: Good use for itertools.dropwhile and itertools.takewhile Nick Mellor <thebalancepro@gmail.com> - 2012-12-04 07:24 -0800
      Re: Good use for itertools.dropwhile and itertools.takewhile Vlastimil Brom <vlastimil.brom@gmail.com> - 2012-12-04 22:08 +0100
    Re: Good use for itertools.dropwhile and itertools.takewhile Nick Mellor <thebalancepro@gmail.com> - 2012-12-04 07:24 -0800
      Re: Good use for itertools.dropwhile and itertools.takewhile Neil Cerutti <neilc@norwich.edu> - 2012-12-04 18:26 +0000
  Re: Good use for itertools.dropwhile and itertools.takewhile Alexander Blinne <news@blinne.net> - 2012-12-04 18:18 +0100
    Re: Good use for itertools.dropwhile and itertools.takewhile DJC <djc@news.invalid> - 2012-12-04 18:28 +0000
      Re: Good use for itertools.dropwhile and itertools.takewhile Alexander Blinne <news@blinne.net> - 2012-12-04 19:48 +0100
        Re: Good use for itertools.dropwhile and itertools.takewhile Ian Kelly <ian.g.kelly@gmail.com> - 2012-12-04 12:37 -0700
          Re: Good use for itertools.dropwhile and itertools.takewhile Alexander Blinne <news@blinne.net> - 2012-12-04 21:33 +0100
          Re: Good use for itertools.dropwhile and itertools.takewhile Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-12-04 21:13 +0000
        Re: Good use for itertools.dropwhile and itertools.takewhile MRAB <python@mrabarnett.plus.com> - 2012-12-04 20:17 +0000
  Re: Good use for itertools.dropwhile and itertools.takewhile Terry Reedy <tjreedy@udel.edu> - 2012-12-04 15:44 -0500
    Re: Good use for itertools.dropwhile and itertools.takewhile Nick Mellor <thebalancepro@gmail.com> - 2012-12-04 17:17 -0800
      Re: Good use for itertools.dropwhile and itertools.takewhile Chris Angelico <rosuav@gmail.com> - 2012-12-06 00:45 +1100
        Re: Good use for itertools.dropwhile and itertools.takewhile Neil Cerutti <neilc@norwich.edu> - 2012-12-05 14:34 +0000
          Re: Good use for itertools.dropwhile and itertools.takewhile Ian Kelly <ian.g.kelly@gmail.com> - 2012-12-05 08:33 -0700
            Re: Good use for itertools.dropwhile and itertools.takewhile Neil Cerutti <neilc@norwich.edu> - 2012-12-05 16:11 +0000
      Re: Good use for itertools.dropwhile and itertools.takewhile Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-12-05 15:32 +0000
      Re: Good use for itertools.dropwhile and itertools.takewhile Ian Kelly <ian.g.kelly@gmail.com> - 2012-12-05 09:16 -0700
      Re: Good use for itertools.dropwhile and itertools.takewhile MRAB <python@mrabarnett.plus.com> - 2012-12-05 17:57 +0000
    Re: Good use for itertools.dropwhile and itertools.takewhile Nick Mellor <thebalancepro@gmail.com> - 2012-12-04 17:17 -0800
      Re: Good use for itertools.dropwhile and itertools.takewhile Neil Cerutti <neilc@norwich.edu> - 2012-12-05 13:29 +0000
        Re: Good use for itertools.dropwhile and itertools.takewhile Nick Mellor <thebalancepro@gmail.com> - 2012-12-05 09:04 -0800
          Re: Good use for itertools.dropwhile and itertools.takewhile MRAB <python@mrabarnett.plus.com> - 2012-12-05 17:57 +0000
          Re: Good use for itertools.dropwhile and itertools.takewhile Neil Cerutti <neilc@norwich.edu> - 2012-12-05 18:16 +0000
            Re: Good use for itertools.dropwhile and itertools.takewhile Nick Mellor <thebalancepro@gmail.com> - 2012-12-05 11:01 -0800
              Re: Good use for itertools.dropwhile and itertools.takewhile Neil Cerutti <neilc@norwich.edu> - 2012-12-05 20:13 +0000
              Re: Good use for itertools.dropwhile and itertools.takewhile Vlastimil Brom <vlastimil.brom@gmail.com> - 2012-12-05 22:36 +0100
                Re: Good use for itertools.dropwhile and itertools.takewhile Neil Cerutti <neilc@norwich.edu> - 2012-12-06 13:06 +0000
                Re: Good use for itertools.dropwhile and itertools.takewhile Vlastimil Brom <vlastimil.brom@gmail.com> - 2012-12-06 15:12 +0100
          Re: Good use for itertools.dropwhile and itertools.takewhile Alexander Blinne <news@blinne.net> - 2012-12-06 14:40 +0100
  Re: Good use for itertools.dropwhile and itertools.takewhile Terry Reedy <tjreedy@udel.edu> - 2012-12-04 17:21 -0500
  Re: Good use for itertools.dropwhile and itertools.takewhile Paul Rubin <no.email@nospam.invalid> - 2012-12-06 13:29 -0800

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