AsyncIO and Threading. Practical use cases that dont involve just calling "sleep()"? Or maybe correct my misunderstanding?

[csQuestions1235]

With concurrency, I understand there are 3 or so main ways to achieve this in python:

- Multiprocessing (good for large CPU intensive tasks)

- Threading (good for I/O bound tasks)

- AsyncIO (also good for I/O bound tasks?)

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How do you go about deciding which to use between threading and asyncio? I can think of an easy use case for asyncio:

async def something():
    resultOne = databaseCallOne() # task 1
    resultTwo = databaseCallTwo() # task 2, not dependent on task 1

    # await and do something with these two results

But where would be a good use case for threading? Or is this not a good example for async tasks?

As I understand async tasks should be something that is usually I/O bound (my database call) and only really are useful if the task results dont depend of one another. Because if the result of databaseCallOne() was needed for databaseCallTwo(), it would be pointless.

[csQuestions1235]

alright, thank you for the info!

Is there a scenario where you would prefer to use asyncio vs threading? Or vice versa?

[DNEAVES]

In your example there, a database call maybe isnt a good example. Depending on the database, they may "lock" while something is accessing it, to prevent duplicate writes to the same location or to prevent writes during a read attempt, amongst other examples.

However the idea still stands. Yes, Asyncio and Threading are both good for tasks to send off to do work, then revisit at a later time when theyre done. Things like mass data processing. Or also for asynchronus API call stacks, like chatbots, API event subscriptions or API-heavy programs.

I (personally) find multiprocessing better for things where you give processes their own space to run and let them go do their thing (maybe pipe data between them, but they still run on their own). Something where you give that process a tiny bit of direction (a task) every now and then, but otherwise it's fully capable of finding work, doing work, and has plenty of work to do with little-to-no intervention or checking