Re: Pylint prefers list comprehension over filter...

From	Christopher Reimer <christopher_reimer@icloud.com>
Newsgroups	comp.lang.python
Subject	Re: Pylint prefers list comprehension over filter...
Date	2016-05-07 12:37 -0700
Message-ID	<mailman.467.1462649844.32212.python-list@python.org> (permalink)
References	(1 earlier) <1462498631.232041.599637409.25D91C08@webmail.messagingengine.com> <mailman.422.1462498634.32212.python-list@python.org> <ngh0hu$4og$1@dont-email.me> <1462503446.248479.599683745.79791DAC@webmail.messagingengine.com> <572E43F0.6060501@icloud.com>

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On 5/5/2016 7:57 PM, Stephen Hansen wrote:
> 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.

My line of code was something I copied off the Internet and modified it 
until it did I exactly what I wanted it to do. That means that the many 
Python 2 code examples available on the Internet are using a redundant 
list operation with Python 3. Isn't that a "smell" that pylint should 
pick up on?

Thank you,

Chris R.

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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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