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Python has had async for 10 years – why isn't it more popular?

(tonybaloney.github.io)
320 points willm | 5 comments | 02 Sep 25 17:24 UTC | HN request time: 0.616s | source
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throwawayffffas ◴[02 Sep 25 21:40 UTC] No.45109435[source]▶
The function coloring is a non starter for me.

I would just rather write JS where everything is async by default.

replies(1): >>45109493 #
1. IshKebab ◴[02 Sep 25 21:44 UTC] No.45109493[source]▶
Everything is not async by default in JS.
replies(2): >>45109573 #>>45110137 #
2. throwawayffffas ◴[02 Sep 25 21:50 UTC] No.45109573[source]▶
I mean everything is running on the runloop, async/await, promises, and callbacks are different flavors of syntactic sugar for the same underlying thing.

In JS you can do:

   async function foo(){...}
   function bar(){foo().then(...);}
In python though async and sync code runs in a fundamentally different way as far as I understand it.
replies(1): >>45109696 #
3. IshKebab ◴[02 Sep 25 22:01 UTC] No.45109696[source]▶
I'm not too familiar with Python async. The only time I used it was to get stderr and stdout out of a subprocess.run() separately. I think anyone using it for performance reasons is insane and should just switch to a more performant language.

Anyway I think the main difference is that in Python you control the event loop whereas in JS there's one fixed event loop and you have no choice about it.

4. fzzzy ◴[02 Sep 25 22:50 UTC] No.45110137[source]▶
I think what they mean is that there are no blocking functions in the standard library except alert, prompt, and confirm. ( are there any others?)
replies(1): >>45112808 #
5. steve_adams_86 ◴[03 Sep 25 06:27 UTC] No.45112808[source]▶
Yeah, you can call async functions without specifying it as such and the script will just carry on regardless of how you're handling it. Totally weird, but also pretty cool. When I first started some 20 years ago that was a major foot gun for me, coming from PHP where functions always returned before the next one was called.