Please explain “Task was destroyed but it is pending!”

Question

Python 3.4.2

I am learning asyncio and I use it to continously listen IPC bus, while gbulb listens to the dbus.

Some side notes:

So I created a fun

Answer 1

The reasons this happens is as explained by @Yeray Diaz Diaz In my case, I wanted to cancel all the tasks that were not done after the first finished, so I ended up cancelling the extra jobs, then using loop._run_once() to run the loop a bit more and allow them to stop:

    loop = asyncio.get_event_loop()
    job = asyncio.wait(tasks, return_when=asyncio.FIRST_COMPLETED)
    tasks_finished,tasks_pending, = loop.run_until_complete(job)
    tasks_done = [t for t in tasks_finished if t.exception() is None]
    if tasks_done == 0:
        raise Exception("Failed for all tasks.")
    assert len(tasks_done) == 1
    data = tasks_done[0].result()
    for t in tasks_pending:
        t.cancel()
        t.cancel()
    while not all([t.done() for t in tasks_pending]):
        loop._run_once()