top 3 wsgi server 2020 code example

Example 1: best python framework

Do you mean best python web framework?
If it is, then use Flask or Django.

Example 2: python wsgi

--- Disclaimer ---
Some of these like Gunicorn, Nginx, uWSGI won't work on windows.
The only WSGI server that I know that work on windows is waitress.

List of WSGI servers you could use:
  - Gunicorn
  - Waitress (I recommend this for windows users)
  - uWSGI
  - Nginx
  - Django (It's built in with WSGI)
  - Apache