Obey the Testing Goat!
Do Nothing Until You Have a Test.
Goat 10 videos.
To testing, see eg. realpython's comparison of test tools: unittest, nose2 and pyTest.
geckodriver på Github.
Selenium: Primarily it is for automating web applications for testing purposes, but is certainly not limited to just that. Boring web-based administration tasks can (and should) also be automated as well.
Django framework for development of web applications.