import asyncio

async def worker():
    try:
        await asyncio.sleep(3600)
    finally:
        await asyncio.sleep(1)

async def main():
    async with asyncio.timeout(0.5):
        async with asyncio.TaskGroup() as tg:
            tg.create_task(worker())
            await asyncio.sleep(0.1)
            tg.cancel()
    print("no error")

asyncio.run(main())

        if self._parent_cancel_requested:
            # If this flag is set we *must* call uncancel().
            if self._parent_task.uncancel() == 0:
                # If there are no pending cancellations left,
                # don't propagate CancelledError.
                propagate_cancellation_error = None
            else:
                propagate_cancellation_error = exceptions.CancelledError()