Ah, so mypy supports fstrings, but not in types. So you can do
Direction = Literal["left", "right"]
But this won't work:
eft = "eft"
ight = "ight"
Direction = Literal[f"l{eft}", f"r{ight}"]
(Yes, this is super contrived, I bad at coming up with examples, but
https://mariusschulz.com/blog/string-literal-types-in-typesc... shows some realistic examples where it's useful in typescript)
