▲ | xg15 2 days ago | |||||||
No, Python's system is more complex and unfortunately overloads "await" to do several things. If you just do
then the call to someOtherAsyncFunction will not spawn any kind of task or delegate to the event loop at all - it will just execute someOtherAsyncFunction() within the task and event loop iteration that myAsyncFunction() is already running in. This is a major difference from JS.If you just did
without await, this would be a fire-and-forget call in JS, but in Python, it doesn't do anything. The statement creates a coroutine object for the someOtherAsyncFunction() call, but doesn't actually execute the call and instead just throws the object away again.I think this is what triggers the "coroutine is not awaited" warning: It's not complaining about fire-and-forget being bad style, it's warning that your code probably doesn't do what you think it does. The same pitfall is running things concurrently. In JS, you'd do:
In Python, the functions will be run sequentially, in the await lines, not in the lines with the function calls.To actually run things in parallel, you have to to
or one of the related methods. The method will schedule a new task and return a future that you can await on, but don't have to. But that "await" would work completely differently from the previous awaits internally. | ||||||||
▲ | everforward 2 days ago | parent [-] | |||||||
I think this is semantically the same thing, though I'm sure your terminology is more correct (not an expert here). If you do `someOtherAsyncFunction()` without await and Python tried to execute similarly to a version with `await`, then the one without await would happen in the same task and event loop iteration but there's no guarantee that it's done by the time the outer function is. Thus the existing task/event loop iteration has to be kept alive or the non-await'ed task needs to be reaped to some other task/event loop iteration. > loop.create_task(asyncFunc()) This sort of intuitively makes sense to me because you're creating a new "context" of sorts directly within the event loop. It's similar-ish to creating daemons as children of PID 1 rather than children of more-ephemeral random PIDs. | ||||||||
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