New submission from ughacks <ugha...@yahoo.com>:
Dear,
I am using
$ python -V
Python 2.6.4
on Ubuntu 9.10
I met a serious bug in s.append(x) operation. If I append a list into another
list, there is a change of content. In the following code, [2,-2,0,0] is
replaced with [-2,-2,0,0] after s.append(x) operaton.
------- begin of code ------
total=[]
for i in range(4):
for j in range(i):
root=[0,0,0,0]
for k in [2,-2]:
for l in [2,-2]:
root[i]=k
root[j]=l
total.append(root)
print root
print total
--------------- end of code -----
Result: each element is correctly generated
[2, 2, 0, 0]
[-2, 2, 0, 0]
[2, -2, 0, 0]
[-2, -2, 0, 0]
[2, 0, 2, 0]
[-2, 0, 2, 0]
[2, 0, -2, 0]
[-2, 0, -2, 0]
[0, 2, 2, 0]
[0, -2, 2, 0]
[0, 2, -2, 0]
[0, -2, -2, 0]
[2, 0, 0, 2]
[-2, 0, 0, 2]
[2, 0, 0, -2]
[-2, 0, 0, -2]
[0, 2, 0, 2]
[0, -2, 0, 2]
[0, 2, 0, -2]
[0, -2, 0, -2]
[0, 0, 2, 2]
[0, 0, -2, 2]
[0, 0, 2, -2]
[0, 0, -2, -2]
But the total list is wrong
[[-2, -2, 0, 0], [-2, -2, 0, 0], [-2, -2, 0, 0], [-2, -2, 0, 0], [-2, 0, -2,
0], [-2, 0, -2, 0], [-2, 0, -2, 0], [-2, 0, -2, 0], [0, -2, -2, 0], [0, -2, -2,
0], [0, -2, -2, 0], [0, -2, -2, 0], [-2, 0, 0, -2], [-2, 0, 0, -2], [-2, 0, 0,
-2], [-2, 0, 0, -2], [0, -2, 0, -2], [0, -2, 0, -2], [0, -2, 0, -2], [0, -2, 0,
-2], [0, 0, -2, -2], [0, 0, -2, -2], [0, 0, -2, -2], [0, 0, -2, -2]]
----------
messages: 100141
nosy: ughacks
severity: normal
status: open
title: bug in s.append(x)
type: compile error
versions: Python 2.6
_______________________________________
Python tracker <rep...@bugs.python.org>
<http://bugs.python.org/issue8023>
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