Use f-strings
Avoid unnecessary casts to str()bool()int()
Ensure file closure
Merge nested ifs
Simplify for-assigns-appends with comprehensions and internal functions
Avoid shadowing internal function names
Initialize variables
Return value directly instead of assign then return
Make some methods static
* Support the "enter" key from a physical keyboard
I often have a usb keyboard dangling from my printer, and got annoyed I couldn't just hit enter from the console.
https://docs.gtk.org/gtk3/signal.Entry.activate.html
* Fix whitespace for linting
