bpo-34790: Document how passing coroutines to asyncio.wait() can be confusing.

[1st1]

https://bugs.python.org/issue34790

[1st1]

cc @elprans

[elprans]

Drop "although".

[asvetlov]

Neat example :)

[1st1]

Neat example :)

What do you think about deprecating the current wait() design and fixing it in a couple releases?

[asvetlov]

I'd like to deprecate passing regular coroutines into gather() as well

[asvetlov]

Creating a task if a coroutine is passed to a function is too... implicit.

[1st1]

I'd like to deprecate passing regular coroutines into gather() as well

Radical :) I agree, it's confusing. Although maybe we can keep gather() as is and just recommend people to use TaskGroups instead. I believe gather() is way more heavily used than wait().

[miss-islington]

Thanks @1st1 for the PR 🌮🎉.. I'm working now to backport this PR to: 3.7.
🐍🍒⛏🤖

[bedevere-bot]

GH-9577 is a backport of this pull request to the 3.7 branch.

[asvetlov]

Yes, people prefer gather() to wait().
I'm ok with not changing gather() but hiding it behind task groups in the documentation.
On the other hand, depreciation is not harmful. We can do it slowly starting from PendingDeprecationWarning

[1st1]

I'm ok with not changing gather() but hiding it behind task groups in the documentation.

Yep!

On the other hand, depreciation is not harmful. We can do it slowly starting from PendingDeprecationWarning

It can be very annoying in large codebases though. I think it's a good idea to use PendingDeprecationWarning for wait() in 3.8.

[asvetlov]

I think it's a good idea to use PendingDeprecationWarning for wait() in 3.8.

+1

[VasiliPupkin256]

This makes a simple timeouted wait even more complicated than it was already. You should consider adding timeout to wait() functions then.

What we had:

await asyncio.wait({event.wait()}, timeout)

Now we have two options:

await asyncio.wait({asyncio.create_task(event.wait())}, timeout)

or

with contextlib.suppress(asyncio.TimeoutError):
    await asyncio.wait_for(event.wait(), timeout)