Seriously, all and any insight and advice appreciated. Thanks.
The problem is futures (async/await) as a concept; JavaScript, Rust, etc all have the same problems.
Take CSP by contrast: https://en.wikipedia.org/wiki/Communicating_sequential_proce...
Any Go function can take a channel, return a channel, or use a channel (and spawn goroutines) internally, unbeknownst to the caller/callee. It may lead to some bad design decisions (code that must not be async may never be), but it won't get in your way when you least need a refactor.
Spinning off a thread for a single small purpose and trying to synchronize with the result seems fine in theory, but it is a very small piece of the larger puzzle of concurrency and usually gets people into trouble once they realize they need more, because anything more complicated than that one use case becomes very tricky.
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I’m not the person you replied to, and I actually don’t have anything against async/await as a pattern where it is needed, but I know that prior to Python getting async/await, there were some moderately popular green threading / coroutine libraries like gevent and eventlet. You would (mostly) just write normal, synchronous Python, and then blocking calls would be intercepted by the runtime and allow other coroutines to take their turn. This felt Pythonic to me at the time, because most code would work in both sync and async environments. You didn’t have to write a separate async version, and you didn’t really have to update old libraries.
The other pre-async/await approach was taken by Tornado and Twisted... basically a form of callback hell. I don't think anyone liked this, but it might have been popular because it worked... and unofficial green threading implementations like gevent/eventlet sometimes broke in interesting ways. (I think officially incorporating a gevent/eventlet-style solution into Python would have overcome most of the issues... but, that's just my speculation.)
I’ve never used Python professionally outside of some short scripts, but it was one of the first languages I used seriously for hobby stuff back during the early days of the Python 3 transition. I never fully understood why Python chose to switch to async/await. Promises can be useful for structured concurrency patterns, but as someone who has been writing Go professionally for a number of years… I just don’t think most code should need to be async-aware.
For a language like Rust, I think async/await makes perfect sense. Rust cannot afford to impose a runtime on everyone, and async/await can be implemented in a very low level, efficient way that gives the developer as much control as they need. This kind of ultra-low-level optimization stuff just isn’t relevant to Python… so, as an outsider, I almost wonder how (in Python) async/await isn’t just a clunkier coroutine system.
If I were to try to rebut my own comment, I would say that async/await was probably chosen because "explicit is better than implicit", and green threading might have been too implicit for the Python community's tastes.
Green threads required extensive monkey patching, and debugging those programs was incredibly hard. Instagram moved from them to async/await and wrote a blog post about it, iirc.
But I agree that Python’s async/await implementation is a bit too low-level and could use better abstractions. A lot of the hate Python async gets is due to the `asyncio` library. It’s a shame that the default library is full of deprecated and gotcha-ridden APIs. Trio attempted to fix these, but adoption has been low.
The community settled on async for the same reason I love Go despite all its faults. It’s flawed, but you can build successful systems with it. Lots of companies still write new services in async Python instead of Go because, as big as the Go community is, Python’s is absolutely ginormous.
Plus, LLMs brought more new people to Python than most other languages, and it’s easier to find Python developers and teach them async than to hire Gophers.