By design asyncio does not allow its event loop to be nested. This presents a practical problem: When in an environment where the event loop is already running it's impossible to run tasks and wait for the result. Trying to do so will give the error "RuntimeError: This event loop is already running".
The issue pops up in various environments, such as web servers, GUI applications and in Jupyter notebooks.
This module es asyncio to allow nested use of asyncio.run and loop.run_until_complete.
pip3 install nest_asyncio
Python 3.5 or higher is required.
import nest_asyncio
nest_asyncio.apply()Optionally the specific loop that needs ing can be given as argument to apply, otherwise the current event loop is used. An event loop can be ed whether it is already running or not. Only event loops from asyncio can be ed; Loops from other projects, such as uvloop or quamash, generally can't be ed.