Python login screen for MariaDB db

[^Bart]

I found this article:

https://www.simplifiedpython.net/python-gui-login/

I used PDO on PHP 7.3 with last MariaDB engine but I'd like to start to 
use Python for a local warehouse software, I found the above guide but I 
need to understand what I should replace from that guide to link the 
script to my MariaDB DB!

I know I need to use this:

#!/usr/bin/python
import MySQLdb

# Open database connection
db = MySQLdb.connect("localhost","root","MyPWD","MyDB")

But after the above code how could I check the login to my user's table?

Regards.
^Bart