async def gen():
    try:
        await asyncio.sleep(0.1)
        yield 'hello'
    except ZeroDivisionError:
        await asyncio.sleep(0.2)
        yield 'world'

g = gen()
v = await g.asend(None)
print(v)                # Will print 'hello' after
                        # sleeping for 0.1 seconds.

v = await g.athrow(ZeroDivisionError)
print(v)                # Will print 'world' after
                        # sleeping 0.2 seconds.