I don't use refactoring tools as much as I probably should. mostly
because I work with small functions with unique names, but I recently
had a case where a variable name
m was everywhere and I wanted it
named better. This was not possible with find and replace, because
there were other
m's in this region.
I first tried the nvim lsp rename, and it failed, Then I pip installed rope, a refactoring tool for python, and it just worked!
pip install rope
Once you have rope installed you can call rename on the variable.