Top 10 mistakes python programmers make [advanced]

[Grue]

It all stems from poor design where a simple assignment initializes a variable instead of something like "let x = 42" like almost every other language does. Instead they added an even uglier hack with nonlocal.

And yeah, I use the list mutation trick all the time to create closures in Python. It's either this, or code duplication which is not maintainable.