What happens when you update a pip package with custom changes to the code

Question

I made some changes to code that came from a package installed via pip. What will happen to those changes when I update the package? Will the changes be erased? Will the upgrade work properly?

Answer 1

The upgrade will probably not work properly; if it does, then it will just overwrite your changes.

Don't do it like this. If you need to make custom changes, fork the library itself - they're mostly on github these days - and install it directly from your fork with pip install -e .