Hi
You should use flake8 for checking PEP8 and a few other things, it's the best tool like that out there.
There are tools that automatically, correctly apply pep8 fixes to any python code so if you want a flag day it's pretty easy to implement. PEP8 has a mode where it checks a diff so you can automatically prevent landing PEP8 regressions.
There are various plugins to use flake8 in most editors.
Thanks ZK