How to add asynchronous tasks as they are needed?

[AlekseyPython]

As I understand, I can perform async- tasks in two ways:
1. Launch asynchronous tasks sequentially (the first task will be FULLY completed and then the second one):

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import asyncio
import time

async def say_after(delay, what):
    await asyncio.sleep(delay)
    print(what)

async def main():
    print(f"started at {time.strftime('%X')}")

    await say_after(1, 'hello')
    await say_after(2, 'world')

    print(f"finished at {time.strftime('%X')}")

asyncio.run(main())

2. Run several tasks in parallel:

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import asyncio

async def factorial(name, number):
    f = 1
    for i in range(2, number + 1):
        print(f"Task {name}: Compute factorial({i})...")
        await asyncio.sleep(1)
        f *= i
    print(f"Task {name}: factorial({number}) = {f}")

async def main():
    # Schedule three calls *concurrently*:
    await asyncio.gather(
        factorial("A", 2),
        factorial("B", 3),
        factorial("C", 4),
    )

asyncio.run(main())

# Expected output:
#
#     Task A: Compute factorial(2)...
#     Task B: Compute factorial(2)...
#     Task C: Compute factorial(2)...
#     Task A: factorial(2) = 2
#     Task B: Compute factorial(3)...
#     Task C: Compute factorial(3)...
#     Task B: factorial(3) = 6
#     Task C: Compute factorial(4)...
#     Task C: factorial(4) = 24

Is it possible somehow, if I understand that tasks don't fully load the system, add more tasks? That is, to get dynamically change the load on the system.

[nilamo]

asyncio.run() should only be called once, as it creates a new event loop. The function asyncio.create_task() can add new coroutines to the event loop, so it'll be run *eventually* (probably whenever the event loop starts over, which might be almost immediately). https://docs.python.org/3/library/asynci...reate_task

Here's your first example, with an extra function added to help demonstrate:

import asyncio

async def say_after(delay, what):
    await asyncio.sleep(delay)
    print(what)

async def speaker(message):
    for delay in range(3):
        await say_after(delay, message)

async def main():
    await say_after(1, "hello")
    await say_after(2, "world")
    task = asyncio.create_task(speaker("extra work"))
    await say_after(1, "hello 2")
    await say_after(2, "world 2")
    await task

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

Output:
hello
world
extra work
hello 2
extra work
world 2
extra work

[AlekseyPython]

nilamo, thank you!