Currently there are a few Protocols https://docs.python.org/3/library/typing.html#protocols defined in the typing module. One that I recently felt like was missing was a typing annotation for classes with a __str__() method defined. Seems like a fairly straightforward implementation.

@runtime_checkable

class SupportsString(Protocol):    
"""An ABC with one abstract method __str__."""

    __slots__ = ()

    @abstractmethod

    def __str__(self) -> str:

        pass

Perhaps there is another way to do this that I am missing?