“RuntimeError: This event loop is already running”; debugging aiohttp, asyncio and IDE “spyder3” in python 3.6.5

Question

I\'m struggling to understand why I am getting the \"RuntimeError: This event loop is already running\" runtime error. I have tried to run snippets of code from \"https://aiohtt

Answer 1

I have the same issue with Spyder, The only solution that worked for me was to use nest_asyncio

install the nest_asyncio by using the command

pip install nest_asyncio

Add the below lines in your file

import nest_asyncio
nest_asyncio.apply()

And the issue must be fixed.

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From the docs's

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 patches asyncio to allow nested use of asyncio.run and loop.run_until_complete.