[Peer Review] Enforce consistent code style

[cthoyt]

More on the theme of "code as the methods section" - I would strongly suggest applying some formatting to the code, as it currently has a mashup of inconsistent styles. This makes it difficult to read. There's also the secondary benefit of finding possible mistakes when doing the cleanup. A really good way to start enforcing consistent code style is to:

1. Apply black. This tools is completely automatic and gets your code into an almost reader-ready state
2. Apply flake8. I'll shamelessly link you to my own blog post, which is exactly written for people who might just first be learning about code formatters, code style checkers, and automation of their respective application.
3. Set up continuous integration to make sure new commits don't break the style rules

Again, I'm happy to help you understand these things and work through it.