Python type annotations were added to be used by an external type checker, so no they are not enforced by the interpreter itself. This was an explicit decision

Python type annotations were added to be used by an external type checker, so no they are not enforced by the interpreter itself. This was an explicit decision: https://peps.python.org/pep-0484/#non-goals https://peps.python.org/pep-0484/#non-goals