[Python-Dev] Using async/await in place of yield expression (original) (raw)

Antoine Pitrou solipsis at pitrou.net
Mon Nov 27 04:12:54 EST 2017

On Mon, 27 Nov 2017 00:41:55 -0800 Nathaniel Smith <njs at pobox.com> wrote:

Since most libraries assume that they control both await and the coroutine runner, they don't tend to give great error messages here (though trio does [2] ;-)). I think this is also why the asyncio docs don't talk about this. I guess in asyncio's case it is technically a semi-public API because you need to know how it works if you're the author of a library like tornado or twisted that wants to integrate with asyncio. But most people aren't the authors of tornado or twisted, and the ones who are already know how this works, so the lack of docs isn't a huge deal in practice...

This does seem to mean that it can be difficult to provide a await method that works with different coroutine runners, though. For example, Tornado Futures implement await for compatibility with the asyncio event loop. But what if Tornado wants to make its Future class compatible with an event loop that requires a different await convention?

Regards

Antoine.

More information about the Python-Dev mailing list