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Groups > comp.lang.python > #92567
| From | Terry Reedy <tjreedy@udel.edu> |
|---|---|
| Subject | Re: zip as iterator and bad/good practices |
| Date | 2015-06-12 19:43 -0400 |
| References | <mles66$sk2$1@speranza.aioe.org> <201506122034.t5CKYYt0025588@fido.openend.se> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.447.1434152635.13271.python-list@python.org> (permalink) |
On 6/12/2015 4:34 PM, Laura Creighton wrote: > The real problem is removing things from lists when you are iterating > over them, not adding things to the end of lists. One needs to iterate backwards. >>> ints = [0, 1, 2, 2, 1, 4, 6, 5, 5] >>> for i in range(len(ints)-1, -1, -1): if ints[i] % 2: del ints[i] >>> ints [0, 2, 2, 4, 6] But using a list comp and, if necessary, copying the result back into the original list is much easier. >>> 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
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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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