> * lack of immutable vectors, alleviated via style conventions Note that mypy/typed python fixes this: if you annotate a function as returning (or accepting)

> * lack of immutable vectors, alleviated via style conventions Note that mypy/typed python fixes this: if you annotate a function as returning (or accepting) a Sequence/Collection/Iterable instead of a List, and attempt to mutate it, you'll get type errors. This is good practice anyway.