Re Bug

[ThaliaKate]

Bug report

Bug description:

# 
import re
t="""\
x=100;
y=200;

if(x = = y){
    std::cout<<"True\n";
}else{
    std::cout<<"False\n";
}
"""
t = re.sub( "= =", "==", t) # outputs x = = y
This has worked in all previous versions until I installed 3.13.3

CPython versions tested on:

3.13

Operating systems tested on:

Windows

[StanFromIreland]

I'm sorry but I cannot reproduce this with your provided code in main/3.14/3.13, can you please show exactly what is printed?

[skirpichev]

Python 3.13.3 (tags/v3.13.3:6280bb5478, Apr  9 2025, 10:07:49) [GCC 12.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import re
... t="""\
... x=100;
... y=200;
... 
... if(x = = y){
...     std::cout<<"True\n";
... }else{
...     std::cout<<"False\n";
... }
... """
... t = re.sub( "= =", "==", t)
... 
>>> print(t)
x=100;
y=200;

if(x == y){
    std::cout<<"True
";
}else{
    std::cout<<"False
";
}

I can't reproduce this on Linux.

[LamentXU123]

Me too can't reproduce the bug on 3.14 windows

[picnixz]

Considering that no one has been able to reproduce this issue, I'll close it. I may suspect that a tab has been replaced by a whitespace somewhere though (it could have been GitHub that replaced it). Namely, if = = is actually =<TAB>=, then it's normal that it wouldn't work. I suggest using re.sub(r'=[ \t]+=', '==', t) in this case instead.