[FIXED] What are the alternatives for sleep to delay functions? how to run asyncio.Timer()?

Issue

The following is a double question but it's significant to know if it could.

After searching for an alternative I found some methods like asyncio.sleep(), asyncio.Timer(), Threading.Timer(), ...etc

However, after making the research in detail I found that anything working with coroutines is the best choice to get rid of the memory lack so, from searching I found something called asyncio.Timer() which is the best choice.

Basically, what I want to do is a game that can handle more than one million events for one million users.

For example, I need to "upgrade building" and this would be an event that will take n of time to upgrade it. Now I would like to make such a workflow to trigger at a specific time when the time of upgrading a building is ready, there are many ways to achieve that like job-crons I know but I need to achieve that by seconds as well not only by minutes like job-crons do as well as I need to go apart from lacking memory when I use traditional way when I use sleep by time.sleep() or by asyncio.sleep().

However, when I used asyncio.Timer() I got AttributeError because Timer is not a method to work with.

Solution

You can use loop.call_at to have similar behavior to threading.Timer, asyncio.Timer does not exist in Python Standard Library.

Note that loop.call_at gets when argument, the value of the argument should be based on loop.time(), so it is internat eventloop time.

import asyncio
from functools import partial


def callback_one() -> None:
    print("Callback_one")


def callback_n(n: int) -> None:
    print(f"Callback {n}")


async def main():
    print("Started")
    loop = asyncio.get_running_loop()
    print(loop.time())
    timer_handler_1 = loop.call_at(loop.time() + 10, callback_one)
    timer_handler_2 = loop.call_at(loop.time() + 5, partial(callback_n, n=5))
    print(timer_handler_1.when(), timer_handler_2.when())
    await asyncio.sleep(20)
    print("Finished")


if __name__ == '__main__':
    asyncio.run(main())

Answered By - Artiom Kozyrev