Python type hints and context managers

Question

How should a context manager be annotated with Python type hints?

import typing

@contextlib.contextmanager
def foo() -> ???:
    yield

Answer 1

With my PyCharm, I do the following to make its type hinting work:

from contextlib import contextmanager
from typing import ContextManager

@contextmanager
def session() -> ContextManager[Session]:
    yield Session(...)