> It would be nice if Python process could allow me to maintain my own
> patched version of Python stdlibs so that I can use it instead of main
> stdlib and quickly switch between them.
It’s free software, you have the right to copy, edit and release it.
As for the technical aspect of easy switching, editing sys.path seems the way to go, or use PYTHONPATH to give your custom stdlib modules to have precedence over the real stdlib. I’ll stop being off-topic now. :)

Tarek, seen my question about distutils2?