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array alice of [:-0] ??

 P: n/a Beginner question! :-) x=[1,2,3,4] for i in range(len(x)): print x[:-i] >>[][1,2,3][1,2][1] 1) The x[:-0] result seems inconsistent to me; I get the idea that -0=0, so it is taken as x[:0] -[] 2) how then should one do this basic left-recursive subsetting (easily). Thanks. ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Jul 18 '06 #1
4 Replies

 P: n/a On 18/07/2006 11:17 PM, guthrie wrote: Beginner question! :-) x=[1,2,3,4] for i in range(len(x)): print x[:-i] >>[] >>[1,2,3] >>[1,2] >>[1] 1) The x[:-0] result seems inconsistent to me; I get the idea that -0=0, so it is taken as x[:0] -[] 2) how then should one do this basic left-recursive subsetting (easily). |>for i in range(len(x), -1, -1): .... print x[:i] .... [1, 2, 3, 4] [1, 2, 3] [1, 2] [1] [] Jul 18 '06 #2

 P: n/a guthrie wrote: Beginner question! :-) x=[1,2,3,4] for i in range(len(x)): print x[:-i] >>[] >>[1,2,3] >>[1,2] >>[1] 1) The x[:-0] result seems inconsistent to me; I get the idea that -0=0, so it is taken as x[:0] -[] that's what you get. 2) how then should one do this basic left-recursive subsetting (easily). I am not sure what you mean, but replacing x[:-i] by x[:len(x)-i] you will get continuous behavior at i==0. Jul 18 '06 #3

 P: n/a On 2006-07-18, guthrie [][1,2,3][1,2][1] 1) The x[:-0] result seems inconsistent to me; I get the idea that -0=0, so it is taken as x[:0] -[] That is correct. Negative indexes are a handy shorthand, but they can give unexpected/strange results in a number of cases. 2) how then should one do this basic left-recursive subsetting (easily). x=[1,2,3,4] lng = len(x) for i in range(lng): print x[:lng-i] -- Antoon Pardon Jul 18 '06 #4

 P: n/a Thanks all!! --------------------- guthrie wrote: Beginner question! :-) x=[1,2,3,4] for i in range(len(x)): print x[:-i] >>[] >>[1,2,3] >>[1,2] >>[1] 1) The x[:-0] result seems inconsistent to me; I get the idea that -0=0, so it is taken as x[:0] -[] 2) how then should one do this basic left-recursive subsetting (easily). Thanks. ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Jul 18 '06 #5