[Python-Dev] More data points (original) (raw)

ncoghlan at iinet.net.au ncoghlan at iinet.net.au
Sun Sep 26 01:47:26 CEST 2004

Quoting Raymond Hettinger <python at rcn.com>:

[Bob Ippolito] > > > >>> x = [] > > > >>> x.extend(-y for y in x) > > > Segmentation fault

I get a MemoryError. To help with get a comprehensive view when I look at this more closely tomorrow, can you try out variations on the theme with other mutables: myset.update deque.extend dict.update dict.fromkeys array.extend

Short answer: all of these work OK for me (i.e. do nothing). Only list.extend suffers from the segmentation fault.

Session transcripts (with bonus X's to trick mailreaders):

[... at localhost src]$ ./python Python 2.4a3 (#16, Sep 21 2004, 17:33:57) [GCC 3.4.1 20040702 (Red Hat Linux 3.4.1-2)] on linux2 Type "help", "copyright", "credits" or "license" for more information. X>> x = [] X>> x.extend(-y for y in x) Segmentation fault [... at localhost src]$ ./python Python 2.4a3 (#16, Sep 21 2004, 17:33:57) [GCC 3.4.1 20040702 (Red Hat Linux 3.4.1-2)] on linux2 Type "help", "copyright", "credits" or "license" for more information. X>> x = set() X>> x.update(-y for y in x) X>> x set([]) X>> from collections import deque X>> x = deque() X>> x.extend(-y for y in x) X>> x deque([]) X>> x = {} X>> x.update(-y for y in x) X>> x {} X>> x.fromkeys(-y for y in x) {} X>> from array import array X>> x = array('B') X>> x.extend(-y for y in x) X>> x array('B')

More information about the Python-Dev mailing list