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Groups > comp.lang.python > #47716
| From | Roy Smith <roy@panix.com> |
|---|---|
| Newsgroups | comp.lang.python |
| Subject | Re: Split a list into two parts based on a filter? |
| Date | 2013-06-11 20:33 -0400 |
| Organization | PANIX Public Access Internet and UNIX, NYC |
| Message-ID | <roy-10ED1B.20334411062013@news.panix.com> (permalink) |
| References | <kp5d9e$2hf$1@panix2.panix.com> <mailman.2992.1370904643.3114.python-list@python.org> <roy-12F8FA.00111311062013@news.panix.com> <mailman.3023.1370964449.3114.python-list@python.org> |
In article <mailman.3023.1370964449.3114.python-list@python.org>,
Serhiy Storchaka <storchaka@gmail.com> wrote:
> 11.06.13 07:11, Roy Smith написав(ла):
> > In article <mailman.2992.1370904643.3114.python-list@python.org>,
> > Roel Schroeven <roel@roelschroeven.net> wrote:
> >
> >> new_songs, old_songs = [], []
> >> [(new_songs if s.is_new() else old_songs).append(s) for s in songs]
> >
> > Thanks kind of neat, thanks.
> >
> > I'm trying to figure out what list gets created and discarded. I think
> > it's [None] * len(songs).
>
> It is the same as your klunky code, but consumes more memory.
Well, continuing down this somewhat bizarre path:
new_songs, old_songs = [], []
itertools.takewhile(
lambda x: True,
(new_songs if s.is_new() else old_songs).append(s) for s in songs)
)
I'm not sure I got the syntax exactly right, but the idea is anything
that will iterate over a generator expression. That at least gets rid
of the memory requirement to hold the throw-away list :-)
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Split a list into two parts based on a filter? roy@panix.com (Roy Smith) - 2013-06-10 16:34 -0400
Re: Split a list into two parts based on a filter? Chris Angelico <rosuav@gmail.com> - 2013-06-11 08:50 +1000
Re: Split a list into two parts based on a filter? Roel Schroeven <roel@roelschroeven.net> - 2013-06-11 00:50 +0200
Re: Split a list into two parts based on a filter? Roy Smith <roy@panix.com> - 2013-06-11 00:11 -0400
Re: Split a list into two parts based on a filter? Serhiy Storchaka <storchaka@gmail.com> - 2013-06-11 18:27 +0300
Re: Split a list into two parts based on a filter? Roy Smith <roy@panix.com> - 2013-06-11 20:33 -0400
Re: Split a list into two parts based on a filter? Phil Connell <pconnell@gmail.com> - 2013-06-12 07:32 +0100
Re: Split a list into two parts based on a filter? Roy Smith <roy@panix.com> - 2013-06-12 07:39 -0400
Re: Split a list into two parts based on a filter? Fábio Santos <fabiosantosart@gmail.com> - 2013-06-12 12:51 +0100
Re: Split a list into two parts based on a filter? Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-06-12 15:06 +0300
Re: Split a list into two parts based on a filter? Terry Reedy <tjreedy@udel.edu> - 2013-06-12 14:07 -0400
Re: Split a list into two parts based on a filter? Serhiy Storchaka <storchaka@gmail.com> - 2013-06-12 19:28 +0300
Re: Split a list into two parts based on a filter? Fábio Santos <fabiosantosart@gmail.com> - 2013-06-12 17:57 +0100
Re: Split a list into two parts based on a filter? Terry Reedy <tjreedy@udel.edu> - 2013-06-12 14:47 -0400
Re: Split a list into two parts based on a filter? Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-06-13 10:43 +0100
Re: Split a list into two parts based on a filter? Chris Rebert <clp2@rebertia.com> - 2013-06-10 16:03 -0700
Re: Split a list into two parts based on a filter? Tim Chase <python.list@tim.thechases.com> - 2013-06-10 18:10 -0500
Re: Split a list into two parts based on a filter? Fábio Santos <fabiosantosart@gmail.com> - 2013-06-11 00:08 +0100
Re: Split a list into two parts based on a filter? alex23 <wuwei23@gmail.com> - 2013-06-11 17:44 -0700
Re: Split a list into two parts based on a filter? Chris Angelico <rosuav@gmail.com> - 2013-06-11 09:12 +1000
Re: Split a list into two parts based on a filter? Peter Otten <__peter__@web.de> - 2013-06-11 02:11 +0200
Re: Split a list into two parts based on a filter? Peter Otten <__peter__@web.de> - 2013-06-11 08:43 +0200
Re: Split a list into two parts based on a filter? Jonas Geiregat <jonas@geiregat.org> - 2013-06-11 08:47 +0200
Re: Split a list into two parts based on a filter? Fábio Santos <fabiosantosart@gmail.com> - 2013-06-11 14:48 +0100
Re: Split a list into two parts based on a filter? rusi <rustompmody@gmail.com> - 2013-06-11 09:37 -0700
Re: Split a list into two parts based on a filter? Fábio Santos <fabiosantosart@gmail.com> - 2013-06-11 18:05 +0100
Re: Split a list into two parts based on a filter? rusi <rustompmody@gmail.com> - 2013-06-11 10:23 -0700
Re: Split a list into two parts based on a filter? Chris Angelico <rosuav@gmail.com> - 2013-06-12 03:37 +1000
Re: Split a list into two parts based on a filter? rusi <rustompmody@gmail.com> - 2013-06-11 11:13 -0700
Re: Split a list into two parts based on a filter? Fábio Santos <fabiosantosart@gmail.com> - 2013-06-11 19:05 +0100
Re: Split a list into two parts based on a filter? Joshua Landau <joshua.landau.ws@gmail.com> - 2013-06-11 15:22 +0100
Re: Split a list into two parts based on a filter? Serhiy Storchaka <storchaka@gmail.com> - 2013-06-11 18:28 +0300
Re: Split a list into two parts based on a filter? Chris Angelico <rosuav@gmail.com> - 2013-06-12 03:28 +1000
Re: Split a list into two parts based on a filter? Roy Smith <roy@panix.com> - 2013-06-11 20:12 -0400
Re: Split a list into two parts based on a filter? Peter Otten <__peter__@web.de> - 2013-06-11 20:13 +0200
Re: Split a list into two parts based on a filter? Peter Otten <__peter__@web.de> - 2013-06-11 20:18 +0200
Re: Split a list into two parts based on a filter? Chris Angelico <rosuav@gmail.com> - 2013-06-12 04:27 +1000
Re: Split a list into two parts based on a filter? Roel Schroeven <roel@roelschroeven.net> - 2013-06-11 22:22 +0200
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