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

tonybaloney.github.io

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

#171

Post by 6r17 »

atomicnumber3 wrote: post #14

The author gets close to what I think the root problem is, but doesn't call it out. The truth is that in python, async was too little, too late. By the time it was introduced, most people who actually needed to do lots of io concurrently had their own workarounds (forking, etc) and people who didn't actually need it had found out how to get by without it (multiprocessing etc). Meanwhile, go showed us what good green…

I feel like async is just an easier way to reason about something but it leaves out a lot of cheating open ; tough sometimes it's just more comfortable to write - but that cheating comes with a lot of hidden responsibilities that are just not presented in python (things like ownership) - even tough it present tools to properly solve these issues - anyone who would really want to dive into technical wouldn't choose python anyway

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

#172

Post by throwaway81523 »

Yoric wrote: post #162
throwaway81523 wrote: post #146

Earlier quoted context omitted.

No, goroutines are preemptive. They avoid async hazards though of course introduce some different ones.

To be fair, it depends on the version of Go. Used to be well-hidden cooperative, these days it's preemptive.

It changed for a reason.

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

#173

Post by game_the0ry »

I will take a couple stabs:

- Async is a legitimately hard to get if you are just starting to learn it, which is probably why its isn't more popular in the python community.

- If you need async, that implies you need hi I/O performance. At that point, you probably should have picked a more performant language + runtime (Java, Node), bc use case should dictate tooling.

- It's not enough to make a language + web framework to be async -- the DB drivers need to be async too (author mentions sqlalechemy got async support in 2023 and django orm is a WIP).

I like python, but not bc its async or multi-threaded. I like it bc when I use it, I know I do not have to worry about those things and the new set of problems I have to handle when I do.

For the i/o and multi-threaded perf, give me java and node (maybe erlang/elixir if I am feeling extra spicy). For the fast and easy scripting, with massive community of open source of talent and high quality libraries (including the vast majority of web app slop), give me python.

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

#174

Post by toast0 »

throwawayffffas wrote: post #148
Dylan16807 wrote: post #82

Earlier quoted context omitted.

Having to put "await" everywhere is very explicit. I'd even say it's equally explicit to a bunch of awkward closures. Why do you say it's less?

Because it hides away the underlying machinery. Everything is in a run loop that does not exist in my codebase. The context switching points are obvious but the execution environment is opaque. At least that's how it looks to me.

The problem isn't that it hides away the machinery. The problem is that it hides some things, but not everything. Certainly a lot of stuff hides behind await/async. But as a naive developer who is used to real threads and green threads, I expected there would be some wait to await on a real thread and all the async stuff would just happen... but instead, if you await, actually you've got to be async too. If you had to write your async code where you gave an eventloop a FD and a callback to run when it was ready, that would be more explicit, IMHO... but it would be so wordy that it would only get used under extreme duress... I've worked on those code bases and they can do amazing things, but if there's any complexity it quickly becomes not worth it.

Green threads are better (IMHO), because they actually do hide all the machinery. As a developer in a language with mature green threads (Erlang), I don't have to know about the machinery[1], I just write code that blocks from my perspective and BEAM makes magic happen. As I understand it, that's the model for Java's Project Loom aka Java Green Threads 2: 2 Green 2 Threads. The first release had some issues with the machinery, but I think I read the second release was much better, and I haven't seen much since... I'm not a Cafe Babe, so I don't follow Java that closely.

[1] It's always nice to know about the machinery, but I don't have to know about it, and I was able to get started pretty quick and figure out the machinery later.

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

#175

Post by LtWorf »

atomicnumber3 wrote: post #14

The author gets close to what I think the root problem is, but doesn't call it out. The truth is that in python, async was too little, too late. By the time it was introduced, most people who actually needed to do lots of io concurrently had their own workarounds (forking, etc) and people who didn't actually need it had found out how to get by without it (multiprocessing etc). Meanwhile, go showed us what good green…

forking and async are totally different things.

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

#176

Post by hoppp »

game_the0ry wrote: post #173

I will take a couple stabs: - Async is a legitimately hard to get if you are just starting to learn it, which is probably why its isn't more popular in the python community. - If you need async, that implies you need hi I/O performance. At that point, you probably should have picked a more performant language + runtime (Java, Node), bc use case should dictate tooling. - It's not enough to make a language + web framew…

To be frank someone who picks python is not doing it because they want the best performance.

Its either because its the only language they know or they just don't really care about performance and want to finish the project fast.

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

#177

Post by pkulak »

atomicnumber3 wrote: post #14

The author gets close to what I think the root problem is, but doesn't call it out. The truth is that in python, async was too little, too late. By the time it was introduced, most people who actually needed to do lots of io concurrently had their own workarounds (forking, etc) and people who didn't actually need it had found out how to get by without it (multiprocessing etc). Meanwhile, go showed us what good green…

Green threads can be nicer to program in, but it’s not like there’s no cost. You still need a stack for every green thread, just like you need one for every normal thread. I think it’s worth it to figure out a good system for stackless async. Something like Kotlin is about as good as it gets. Rust is getting there, despite all the ownership issues, which would exist in green threads too.

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

#178

Post by gddgb »

LtWorf wrote: post #175
atomicnumber3 wrote: post #14

The author gets close to what I think the root problem is, but doesn't call it out. The truth is that in python, async was too little, too late. By the time it was introduced, most people who actually needed to do lots of io concurrently had their own workarounds (forking, etc) and people who didn't actually need it had found out how to get by without it (multiprocessing etc). Meanwhile, go showed us what good green…

forking and async are totally different things.

[dead]

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

#179

Post by game_the0ry »

hoppp wrote: post #176
game_the0ry wrote: post #173

I will take a couple stabs: - Async is a legitimately hard to get if you are just starting to learn it, which is probably why its isn't more popular in the python community. - If you need async, that implies you need hi I/O performance. At that point, you probably should have picked a more performant language + runtime (Java, Node), bc use case should dictate tooling. - It's not enough to make a language + web framew…

To be frank someone who picks python is not doing it because they want the best performance. Its either because its the only language they know or they just don't really care about performance and want to finish the project fast.

Agreed, bc I have been that "someone."

And there is nothing wrong with that. In fact, this should be the norm.

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

#180

Post by lyu07282 »

int_19h wrote: post #161
mjd wrote: post #37

I haven't read the article yet, but I do have something to contribute: several years ago I was ay PyCon and saw a talk in which someone mentioned async. I was interested and wanted to learn to use it. But I found there was no documentation at all! The syntax was briefly described, but not the semantics. I realized, years later, that the (non-)documentation was directed at people who were already familiar with the fea…

FWIW Python got async/await before JavaScript did. I believe at the time the main inspiration was C#.

JavaScript was always single-threaded asynchronous, the added async/await keywords were just syntactic sugar. Node.js became popular before it as well, though I found at the time it was difficult to avoid callback hell similar to using libuv directly in C.
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