[python] How to remove pip package after deleting it manually

I met the same issue while experimenting with my own Python library and what I've found out is that pip freeze will show you the library as installed if your current directory contains lib.egg-info folder. And pip uninstall <lib> will give you the same error message.

  1. Make sure your current directory doesn't have any egg-info folders
  2. Check pip show <lib-name> to see the details about the location of the library, so you can remove files manually.