[docs] A bug in python 2.7.12 and 3.5.2 ?

[Xiang Gao]

Hi，


I noticed something strange when initializing an empty list of a given size using:


>>> a = [ [] ] * 3   # create an empty list of size 3, with each element being an empty list

>>> a[1].append('a')   # modify element[1], leave element[0] and [2] unchanged.

>>> a

>>> [ ['a'], ['a'], ['a'] ]   # Result suggests all elements have shared references, that doesn't look right.


This is not critical, since I can re-initialize the empty list: (But, it would be nice to fix it. )


>>> for i in range(len(a)):

>>>     a[i] = []

>>>

>>> a[1].append('a')

>>> a

>>> [ [], ['a'], [] ]   # This is what I expected.


Thanks for your attention !


Xiang

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/docs/attachments/20170410/bde258e0/attachment.html>