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| References | <mles66$sk2$1@speranza.aioe.org> <201506122034.t5CKYYt0025588@fido.openend.se> <mailman.447.1434152635.13271.python-list@python.org> <e5d750bd-d7e3-4d93-9794-e9f16a4b40bd@googlegroups.com> |
|---|---|
| Date | 2015-06-13 10:26 +1000 |
| Subject | Re: zip as iterator and bad/good practices |
| From | Chris Angelico <rosuav@gmail.com> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.450.1434155212.13271.python-list@python.org> (permalink) |
On Sat, Jun 13, 2015 at 10:02 AM, <sohcahtoa82@gmail.com> wrote:
>> >>> ints = [0, 1, 2, 2, 1, 4, 6, 5, 5]
>> >>> ints[:] = [i for i in ints if not i % 2]
>> >>> ints
>> [0, 2, 2, 4, 6]
>>
>>
>> --
>> Terry Jan Reedy
>
> On the second line of your final solution, is there any reason you're using `ints[:]` rather than just `ints`?
If you use "ints = [...]", it rebinds the name ints to the new list.
If you use "ints[:] = [...]", it replaces the entire contents of the
list with the new list. The two are fairly similar if there are no
other references to that list, but the replacement matches the
mutation behaviour of remove().
def just_some(ints):
ints[:] = [i for i in ints if not i % 2]
ChrisA
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zip as iterator and bad/good practices Fabien <fabien.maussion@gmail.com> - 2015-06-12 17:00 +0200
Re: zip as iterator and bad/good practices Fabien <fabien.maussion@gmail.com> - 2015-06-12 17:05 +0200
Re: zip as iterator and bad/good practices Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-12 09:26 -0600
Re: zip as iterator and bad/good practices Fabien <fabien.maussion@gmail.com> - 2015-06-12 17:34 +0200
Re: zip as iterator and bad/good practices Fabien <fabien.maussion@gmail.com> - 2015-06-12 17:59 +0200
Re: zip as iterator and bad/good practices Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-12 17:22 +0100
Re: zip as iterator and bad/good practices Laura Creighton <lac@openend.se> - 2015-06-12 22:34 +0200
Re: zip as iterator and bad/good practices Terry Reedy <tjreedy@udel.edu> - 2015-06-12 19:27 -0400
Re: zip as iterator and bad/good practices Terry Reedy <tjreedy@udel.edu> - 2015-06-12 19:43 -0400
Re: zip as iterator and bad/good practices sohcahtoa82@gmail.com - 2015-06-12 17:02 -0700
Re: zip as iterator and bad/good practices Chris Angelico <rosuav@gmail.com> - 2015-06-13 10:26 +1000
Re: zip as iterator and bad/good practices sohcahtoa82@gmail.com - 2015-06-12 17:39 -0700
Re: zip as iterator and bad/good practices jimages <jimages123@gmail.com> - 2015-06-13 13:32 +0800
Re: zip as iterator and bad/good practices Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-13 07:17 +0000
Re: zip as iterator and bad/good practices Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2015-06-13 13:48 +0100
Re: zip as iterator and bad/good practices Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-13 16:16 +0000
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