This appears to be the case. I'm not a python programmer, but a quick google shows that you've assigned a reference, because the type is mutable. So var1 and var2 are references to the same object ...

This is a script I wrote for some folks to swap generic fields in job files. It's really a demo of my style. - RockoSharp/Example_Python ...

Applying sequence or mapping pattern on a generic variable makes that case unreachable, and false positive reportUnnecessaryComparison is reported (if enabled). $ pyright ma.py ma.py ma.py:3:13 - ...