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Re: Pylint prefers list comprehension over filter...

Path csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail
From Stephen Hansen <me+python@ixokai.io>
Newsgroups comp.lang.python
Subject Re: Pylint prefers list comprehension over filter...
Date Thu, 05 May 2016 19:57:26 -0700
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On Thu, May 5, 2016, at 07:46 PM, Dan Sommers wrote:
> On Thu, 05 May 2016 18:37:11 -0700, Stephen Hansen wrote:
> 
> >     ''.join(x for x in string if x.isupper())
> 
> > The difference is, both filter and your list comprehension *build a
> > list* which is not needed, and wasteful. The above skips building a
> > list, instead returning a generator ...
> 
> filter used to build a list, but now it doesn't (where "used to" means
> Python 2.7 and "now" means Python 3.5; I'm too lazy to track down the
> exact point(s) at which it changed):

Oh, didn't know that. Then again the OP was converting the output of
filter *into* a list, which wasted a list either way.

-- 
Stephen Hansen
  m e @ i x o k a i . i o

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Thread

Re: Pylint prefers list comprehension over filter... Stephen Hansen <me@ixokai.io> - 2016-05-05 18:37 -0700
  Re: Pylint prefers list comprehension over filter... Dan Sommers <dan@tombstonezero.net> - 2016-05-06 02:46 +0000
    Re: Pylint prefers list comprehension over filter... Chris Angelico <rosuav@gmail.com> - 2016-05-06 12:55 +1000
    Re: Pylint prefers list comprehension over filter... Stephen Hansen <me+python@ixokai.io> - 2016-05-05 19:57 -0700
      Re: Pylint prefers list comprehension over filter... Steven D'Aprano <steve@pearwood.info> - 2016-05-06 22:42 +1000
    Re: Pylint prefers list comprehension over filter... Dan Sommers <dan@tombstonezero.net> - 2016-05-06 03:07 +0000
      Re: Pylint prefers list comprehension over filter... Chris Angelico <rosuav@gmail.com> - 2016-05-06 13:18 +1000
    Re: Pylint prefers list comprehension over filter... Christopher Reimer <christopher_reimer@icloud.com> - 2016-05-07 12:37 -0700

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