It seems Python asynchronous programming is gaining momentum but still is quite hairy to get started with, so it's good to see this kind of quick intros popping up. Thanks. :-)
I just wanted to note that the async flow diagram you expose in your article is a bit misleading, as it is demonstrating one specific implementation of asynchronous programming — i.e. callback style async. I heard that this is how Tornado was implemented originally, but that asyncio uses a different async implementation.
From what I know, asyncio uses generators to implement coroutines, i.e. functions that can be "paused" and "resumed" at anytime. These tasks are run by the event loop (probably in a round-robin fashion), such that every time a task awaits, it gives control back to the event loop which allows the next task to run for a bit, until it awaits or terminates.
This cooperative style is what justifies why, as you noted, async is "all-in": if any task blocks, the whole thing collapses back into a good ol' synchronous flow.
So, in this sense, asyncio is more task-based than callback-based. :-)
It seems Python asynchronous programming is gaining momentum but still is quite hairy to get started with, so it's good to see this kind of quick intros popping up. Thanks. :-)
I just wanted to note that the async flow diagram you expose in your article is a bit misleading, as it is demonstrating one specific implementation of asynchronous programming — i.e. callback style async. I heard that this is how Tornado was implemented originally, but that asyncio uses a different async implementation.
From what I know, asyncio uses generators to implement coroutines, i.e. functions that can be "paused" and "resumed" at anytime. These tasks are run by the event loop (probably in a round-robin fashion), such that every time a task
awaits, it gives control back to the event loop which allows the next task to run for a bit, until itawaits or terminates.This cooperative style is what justifies why, as you noted, async is "all-in": if any task blocks, the whole thing collapses back into a good ol' synchronous flow.
So, in this sense, asyncio is more task-based than callback-based. :-)
Thanks for making that clear, I wanted to avoid mentioning such hairy details in an introductory article. :)
As I am saying in the article,
explaining a potential async flow..
Sure! Async can be tough to wrap one’s head around, so it was a good idea to stick to a high-level intro here.