cancel_others.py

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}")
    return name, f

async def main():
    tasks = [
      asyncio.create_task(c) for c in [
        factorial("A", 2),
        factorial("B", 3),
        factorial("C", 4),
    ]]

    done, pending = await asyncio.wait(tasks, return_when=asyncio.FIRST_COMPLETED)
    
    if name == "A":
        for t in pending:
            t.cancel()

asyncio.run(main())