Comment by Xixi | Hacker News Reader

Comment by Xixi | Hacker News Reader

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Long term Python user: if I want to do something asynchronously I reach for Go or Elixir (unless it's just way more practical to do it right there in Python). Adding function colors [1] might have been a practical decision, but was IMHO a mistake.

Why do I have to decide if my function is synchronous or not when I write it? I don't want to do that, I want to write only one function that can be called synchronously or asynchronously. In Go or Elixir, the decision is made by the caller, not by the API designer.

Which leads me to a parallel universe: Go-like asynchronicity should have been introduced with Python 3, when backward compatibility was explicitely broken. The gain of switching to Python 3 would then also have been a much easier sell than "just" fixing strings.

Of course, there are probably a thousand things that I'm overlooking, but this is my feeling...

[1] https://journal.stuffwithstuff.com/2015/02/01/what-color-is-...

> Why do I have to decide if my function is synchronous or not when I write it?

I feel that sync and async functions are fundamentally different. In python coroutine is really just a function you can pause and while it might seem like it's the same thing as a normal function it's actually very different algorithmic-ally speaking as you can include a lot of low level optimizations which is really what async code is all about — getting rid of that IO waiting.

I love async python but after working with it for better half of a year now it is often a bit tiring as you've pointed out. It feels a bit like a patch to the language rather than a feature even with the newest 3.9 version.

Btw you might like https://trio.readthedocs.io which makes asyncio much more bearable!

Is that because the Python interpreter has to explicitly handle coroutines differently from normal functions?

One difference for Elixir/Erlang (which GP mentioned) is that the BEAM VM can interrupt any function by default. (There's a few exceptions when you deal with native code and other things)

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