I'm writing my own webserver in python, my only purpose to this is to learn python and to force myself to do TDD and to write more functional code instead of OO

I'm writing my own webserver in python, my only purpose to this is to learn python and to force myself to do TDD and to write more functional code instead of OO or procedural code with side effects. I would like to have a fully working webserver with threads and serving full html pages.