class sx:
    def __init__(self, vl):
        self.vv = vl

    def __enter__(self):
        try:
            print("in enter")
            sleep(100)
            print(2+self.vv)

        except (Exception, KeyboardInterrupt) as exc:   # WHEN this line is `except Exception as exc`, then it does not catch KeyboardInterrupt. Why? - KeyboardInterrupt is not an exception? :S
            print("innner exception")
            self.__exit__(exc)

    def __exit__(self, exc, *args):
        print("exiting")

with sx('a'):
    print(2)