Know of any good Git repos to "reverse engineer" in order to learn more? (Python)

I'm looking to start getting away from writing basic scripts and learning more about actual programs by checking out functional programs. Does anyone know of some well documented projects that could be read form an outsider's perspective and understood to good extent?

I liked some of the Python repos that are specifically about reverse engineering but I would like to check out a full-fledged program's source to learn more about guis, network requests and etc.