Use Gunicorn With Nginx On Ubuntu Without Any Framework

I Have A Code That Runs Well With gunicorn -b :8080 web:Main In Ubuntu 16.04:

#!/usr/bin/python
# -*- Coding: UTF-8 -*-

def Main(env,start_response):
    start_response('200 OK', [('Content-Type','text/html')])
    data = "<h1>It Works!</h1>"
    return data

Now I Want To Configure Nginx To Use Gunicorn To Serve Python Apps,I've Read The Docs But I Couldn't Understand How To Do That (So I Don't Need To Use gunicorn Command)

I Also Searched A Lot But All The Results Used Django,Flask And VirtualEnv. What I Need Is "Python Web Development From Scratch" In Ubuntu.

Is It Possible To Do This Without Any Framework Or Is It Recommended?