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| References | <efe9d48e-9aaf-4e68-aa26-c83da32e80f5@googlegroups.com> <18a4709f-47c8-41f7-87d5-08bbb00166b6@googlegroups.com> <mailman.63.1433254823.13271.python-list@python.org> <11005554-e89f-407c-8720-fae1bb3fced8@googlegroups.com> |
|---|---|
| From | Ian Kelly <ian.g.kelly@gmail.com> |
| Date | 2015-06-03 16:36 -0600 |
| Subject | Re: How to access the low digits of a list |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.137.1433371024.13271.python-list@python.org> (permalink) |
On Wed, Jun 3, 2015 at 3:08 PM, Rustom Mody <rustompmody@gmail.com> wrote: > On Tuesday, June 2, 2015 at 7:50:58 PM UTC+5:30, Ian wrote: >> On Tue, Jun 2, 2015 at 6:35 AM, Rustom Mody wrote: >> > For that matter even this works >> > But I am not sure whats happening or that I like it >> > >> >>>> [x[-2:] for x in lines] >> > ['12', '42', '49', '56', '25', '36', '49', '64', '81', '00'] >> >> x[-2:] selects all items in the sequence with index i such that len(x) >> - 2 <= i < len(x). For a sequence of length 2 or less, that's the >> entire sequence. > > Thanks -- learn something > So it means that indices can give indexerror; slices cannot? > Seems fair enough put that way, but is visually counterintuitive Yes. The rule I paraphrased above is stated at https://docs.python.org/3/library/stdtypes.html#common-sequence-operations -- scroll down to note 4. I don't know if there's anything that clearly states that sequence slicing can't raise IndexError, but it is at least implied by the above, and it is certainly true of all builtin sequence types.
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How to access the low digits of a list fl <rxjwg98@gmail.com> - 2015-06-02 05:23 -0700
Re: How to access the low digits of a list Joel Goldstick <joel.goldstick@gmail.com> - 2015-06-02 08:32 -0400
Re: How to access the low digits of a list Frank Stutzman <stutzman@cat2.kjsl.com> - 2015-06-02 12:34 +0000
Re: How to access the low digits of a list Rustom Mody <rustompmody@gmail.com> - 2015-06-02 05:35 -0700
Re: How to access the low digits of a list Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-02 08:19 -0600
Re: How to access the low digits of a list Rustom Mody <rustompmody@gmail.com> - 2015-06-03 14:08 -0700
Re: How to access the low digits of a list Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-03 22:41 +0100
Re: How to access the low digits of a list Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-03 16:36 -0600
Re: How to access the low digits of a list Steven D'Aprano <steve@pearwood.info> - 2015-06-04 23:27 +1000
Re: How to access the low digits of a list Steven D'Aprano <steve@pearwood.info> - 2015-06-03 01:11 +1000
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