How to add coroutine to a running event loop?

[nilamo]

Don't use await until you want to stop adding things to the event loop. Whatever you want to be running together, add to the event loop, and then after they're all added is when you await the various tasks. Here's an example:

import asyncio

async def worker():
    print("Starting work")
    await asyncio.sleep(5)
    print("Work complete")

async def other_worker():
    print("Starting other worker")
    await asyncio.sleep(2)
    print("Other worker complete")

async def third_worker():
    print("Starting third worker")
    await asyncio.sleep(1)
    print("Third worker complete")

async def main():
    print("Starting workers")
    tasks = []
    tasks.append(asyncio.ensure_future(worker()))
    tasks.append(asyncio.ensure_future(other_worker()))

    print("First two workers added to the event loop.")
    for task in tasks:
        await task

    print("Adding third worker to the event loop.")
    await third_worker()
    # in this case, this is the same thing
    await asyncio.ensure_future(third_worker())

asyncio.run(main())

Output:
Starting workers
First two workers added to the event loop.
Starting work
Starting other worker
Other worker complete
Work complete
Adding third worker to the event loop.
Starting third worker
Third worker complete
Starting third worker
Third worker complete