how to add a coroutine to a running asyncio loop?

Question

How can one add a new coroutine to a running asyncio loop? Ie. one that is already executing a set of coroutines.

I guess as a workaround one could wait for existing coroutines to complete and then initialize a new loop (with the additional coroutine). But is there a better way?

Answer 1

You can use create_task for scheduling new coroutines:

import asyncio  async def cor1():     ...  async def cor2():     ...  async def main(loop):     await asyncio.sleep(0)     t1 = loop.create_task(cor1())     await cor2()     await t1  loop = asyncio.get_event_loop() loop.run_until_complete(main(loop)) loop.close() 

Answer 2

To add a function to an already running event loop you can use:

asyncio.ensure_future(my_coro())

In my case I was using multithreading (threading) alongside asyncio and wanted to add a task to the event loop that was already running. For anyone else in the same situation, be sure to explicitly state the event loop (as one doesn't exist inside a Thread). i.e:

In global scope:

event_loop = asyncio.get_event_loop() 

Then later, inside your Thread:

asyncio.ensure_future(my_coro(), loop=event_loop)