This is a followup question to /a/62529343/3358488

There, as well in other places, asyncio.create_task(c) is described as “immediately” running the coroutine c, when compared to simply calling the coroutine, which is then only executed when it is awaited.

It makes sense if you interpret “immediately” as “without having to await it”, but in fact a created task is not executed until we run some await (possibly for other coroutines) (in the original question, slow_coro started being executed only when we await fast_coro).

However, if we do not run any await at all, the tasks are still executed (only one step, not to completion) at the end of the program:

import asyncio

async def counter_loop(x, n):
    for i in range(1, n + 1):
        print(f"Counter {x}: {i}")
        await asyncio.sleep(0.5)
    return f"Finished {x} in {n}"


async def main():
    slow_task = asyncio.create_task(counter_loop("Slow", 4))
    fast_coro = asyncio.create_task(counter_loop("Fast", 2))
    print("Created tasks")
    for _ in range(1000):
        pass
    print("main ended")

asyncio.run(main())
print("program ended")

the output is

Created tasks
main ended
Counter Slow: 1
Counter Fast: 1
program ended

I am curious: why are the two created tasks executed at all if there was no await being run anywhere?