I actually posted this in python-ideas and I was quickly suggested to come here instead: """ It would be useful to take advantage of the `LiteralString` or `Literal` type hints to add structural validation to literals. For *example*, if these could be subclassed to add a validation method: class MyLiteral(LiteralString): def __validate__(self): ... or extended to allow something like regex in there generic type parameter: Literal[r"\w+"] LiteralString[r"\w+"] then specific kinds of literal string can be "enforced" by static type checkers. Then IDEs could at the very least highlight that a string literal is not valid. I stress these are just examples, the goal is to have a way to tell a static type checker what the structure of a string literal has to be. """