Skip to main content
The 2026 Annual Developer Survey is live— take the Survey today!

Timeline for answer to How slicing in Python works by Hans Nowak

Current License: CC BY-SA 4.0

Post Revisions

14 events
when toggle format what by license comment
Aug 5, 2025 at 8:56 comment added user29120650 @endolith x[::-1][:k] gets the last k items even if k = 0. Unfortunately, it also copies the entire list first, if the python docs are actually correct about their claims. But why do you need the reverse of the last k items?
S Nov 20, 2024 at 10:26 history rollback Hans Nowak
Rollback to Revision 3 - Edit approval overridden by post owner or moderator
Nov 4, 2024 at 16:56 history suggested jolammi CC BY-SA 4.0
The ascii diagram was wrongly formatted, fixed to match the linked Python documentation
Oct 31, 2024 at 18:01 review Suggested edits
S Nov 20, 2024 at 10:26
S Nov 17, 2023 at 9:06 history suggested Samuel RIGAUD CC BY-SA 4.0
Fix not aligned indexes + update documentation link
Nov 15, 2023 at 18:21 review Suggested edits
S Nov 17, 2023 at 9:06
Apr 15, 2021 at 1:04 comment added aguadopd Addendum to my comment: see my answer with diagrams below: stackoverflow.com/a/56332104/2343869
Apr 5, 2021 at 21:32 comment added Javier Ruiz @aguadopd You are absolutely right. The solution is to have the indices shifted to the right, centered just below the characters, and notice that the stop is always excluded. See another response just below.
Jul 6, 2019 at 20:07 comment added endolith But there's no way to collapse to an empty set starting from the end (like x[:0] does when starting from the beginning), so you have to special-case small arrays. :/
May 27, 2019 at 20:05 comment added aguadopd This suggestion works for positive stride, but does not for a negative stride. From the diagram, I expect a[-4,-6,-1] to be yP but it is ty. What always work is to think in characters or slots and use indexing as a half-open interval -- right-open if positive stride, left-open if negative stride.
Jan 14, 2019 at 2:33 review Suggested edits
Jan 14, 2019 at 6:44
Dec 22, 2017 at 8:05 review Suggested edits
Dec 22, 2017 at 11:11
Sep 18, 2017 at 11:02 history edited kenorb CC BY-SA 3.0
Improves post formatting.
Feb 3, 2009 at 22:49 history answered Hans Nowak CC BY-SA 2.5