gh-125289: Update sample code in asyncio-task.rst

[galmyk]

gh-125289: Update sample code in asyncio-task.rst

This will change coroutines sample code in the Awaitables section and make the example clearer.

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[JacobCoffee]

this lgtm, but more broadly: i find this example weird in general that if i as a new user copy and paste it it just throws an error.

i think it would be nice to scour the documentation and "split" examples into working/non-working and denote them as such... @willingc thoughts?

[galmyk]

@JacobCoffee I agree with splitting working and not working codes. But in this case, code works, just prints a warning:

/home/gmt/a.py:10: RuntimeWarning: coroutine 'nested' was never awaited
  nested()  # will raise a "RuntimeWarning".
RuntimeWarning: Enable tracemalloc to get the object allocation traceback
42

I'm not native english speaker, So I fear my wording in the following line's comment is not correct:

ested()  # will raise a "RuntimeWarning".

It just prints the warning! If it is wrong, please propose a better comment.
Or is it better to remove that command?

[willingc]

this lgtm, but more broadly: i find this example weird in general that if i as a new user copy and paste it it just throws an error.

i think it would be nice to scour the documentation and "split" examples into working/non-working and denote them as such... @willingc thoughts?

Hmm... there are a couple of concepts at work here: async/await, nesting coroutines, and example behavior

I think the use of main() provides a bit more confusion since it is an async function in the example to illustrate nesting. It may be better to use something other than main maybe outer().

Where print() is placed is a bit of a red herring, since it's the async/await nesting that governs behavior.

I do think it makes sense to improve this section of docs, but I want to make sure that we do it in a way that gets the point across clearly about nesting.