Python bug I guess, have a look
1469
Is there a difference between "==" and "is"?
13801
How do I report a bug?
143595
How to step through Python code to help debug issues?
141442
Why does my string comparison fail?
61020
Python extend with an empty list bug?
35503
Understanding Python's "is" operator
110557
Weird list behavior in class
72675
I don't understand why this is causeing my program to crash?
58599
Looks to be an obscure page rendering problem
154907
Possible bug with \implies and \Longrightarrow -- there's a dot in the middle of it
139053
Scoping problem?
89549
Can anyone explain this 'variable does not exist error'?
156253
Why is a method not identical to itself?
17005
polyglossia or bidi bug: [\d\.] gets inverted to [\.\d]
2266
Why is my variable local in one 'while read' loop, but not in another seemingly similar loop?
46672
Getting strange output when printing result of a string comparison
64455
Bug in editor for numbered lists?