Add a API to start a coroutine.

[ZTG0421]

Feature or enhancement

Proposal:

Add a new API to behave like loop.run_until_complete(asyncio.sleep(0)), which runs all tasks in the loop until the first await. This helps to return control to the main thread like in JavaScript, instead of returning to the event loop.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

[issamhaimour]

Feature or enhancement

Proposal:

Add a new API to behave like loop.run_until_complete(asyncio.sleep(0)), which runs all tasks in the loop until the first await. This helps to return control to the main thread like in JavaScript, instead of returning to the event loop.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

[ZeroIntensity]

We already sort of have this. It's called an eager task factory, which will immediately run a task until its first await upon creating it. Otherwise, just use next(coro).

[ZTG0421]

My point is when executing all async task reaches the first await,exit the event loop.

[graingert]

I think it would be better to open a discussion on https://discuss.python.org/c/async-sig/20 first and show some example code of what sort of program would need this feature

[ZTG0421]

I have consulted materials in other languages. To be precise, what I mean is to provide an API that does something when the event loop is idle.

[graingert]

Ah there's https://anyio.readthedocs.io/en/stable/api.html#anyio.wait_all_tasks_blocked

In anyio It's a bit of a hack, but if it were implemented directly in asyncio could be much nicer

This isn't what loop.run_until_complete(asyncio.sleep(0)) does which isn't very useful and directly running the loop is discouraged - you should use asyncio.run