1.py

from contextlib import contextmanager
from typing import Any


@contextmanager
def foo() -> Any:
    print("1 before")
    yield
    print("1 after")


class dual_foo:
    def __init__(self, *args, **kwargs):
        self.__call__(*args, **kwargs)

    def __enter__(self, *args, **kwargs):
        print("enter")

    def __exit__(self, exc_type, exc_val, exc_tb):
        print("cleanup")

    def __call__(self, *args, **kwargs):
        print("run")


if __name__ == "__main__":
    with dual_foo():
        pass

    dual_foo()

run
enter
cleanup
run