class MyExc(Exception):
    pass

import itertools

async def agenfn():
    for i in itertools.count():
        try:
            yield i
        except MyExc:
            pass


agen = agenfn()

try:
    agen.asend(None).send(None)
except StopIteration as e:
    print(f"{e.value=}")

athrow = agen.athrow(MyExc)

try:
    athrow.throw(MyExc)
except StopIteration as e:
    print(f"{e.value=}")

try:
    athrow.throw(MyExc)
except RuntimeError:
    print("good")
except StopIteration as e:
    print(f"bad {e.value=}")