PostgreSQL driver does not load with PyQt5

Question

I am having a problem when trying to connect to PostgreSQL from PyQt5, the following simple code gives me a

'Driver not loaded Driver not loaded"

error message. I am newbie in this and have no idea what to do.

Here is the code:

from PyQt5 import QtSql

db = QtSql.QSqlDatabase.addDatabase("QPSQL")
print (db.lastError().text())

I'm using Python36 on Windows 10