One thing about https://www.python.org/dev/peps/pep-0484/ is that it makes comments potentially semantically meaningful. Unfortunately the AST doesn't carry comments with it in any way, making it difficult to build a tool to implement a linter for PEP 484 using purely the ast module. Even if comments were carried along side-band and could do correlation by line number would be useful in this scenario.

I thought an issue had previously existed for this topic but I could find it.