asyncio - run coroutine in the background

Marko Rauhamaa marko at pacujo.net
Sat Feb 20 04:28:42 EST 2016


Paul Rubin <no.email at nospam.invalid>:

> I've just felt depressed whenever I've looked at any Python async
> stuff. I've written many Python programs with threads and not gotten
> into the trouble that people keep warning about.

Programming-model-wise, asyncio is virtually identical with threads. In
each, I dislike the implicit state concept. I want the state to stand
out with big block letters.

> I've just felt depressed whenever I've looked at any Python async
> stuff. I've written many Python programs with threads and not gotten
> into the trouble that people keep warning about. But I haven't really
> understood the warnings, so maybe they know something I don't. I just
> write in a multiprocessing style, with every mutable object owned by
> exactly one thread and accessed only by RPC through queues, sort of a
> poor man's Erlang. There's a performance hit but there's a much bigger
> one from using Python in the first place, so I just live with it.

Good for you if you have been able to choose your own programming model.
Most people have to deal with a legacy mess. Also, maintainers who
inherit your tidy code might not be careful to ship only nonmutable
objects in the queues.

Your way of using threads works, of course, with the caveat that it is
not possible to get rid of a blocking thread from the outside. With
asyncio, you can at least cancel tasks.


Marko


More information about the Python-list mailing list