I read a lot of the aiohttp related blogs and examples. I think I understand them but when I try to integrate that "knowledge" into the structure of my own application there are some problems. Below is a minimal (not) working example representing this structure.
I assume I have a grounded misunderstanding of how the structure of such a program should look like.
The main problem is the RuntimeError: This event loop is already running. I kind of understand the root of it but do not know how to go around it.
Secondary there are two warnings.
sys:1: RuntimeWarning: coroutine 'wait' was never awaited sys:1: RuntimeWarning: coroutine 'FetchAsync._fetch' was never awaited This is the MWE
#!/usr/bin/env python3 # -*- coding: utf-8 -*- import asyncio import aiohttp class FetchAsync: def __init__(self): pass def _get_loop(self): try: loop = asyncio.get_event_loop() except RuntimeError: loop = asyncio.new_event_loop() asyncio.set_event_loop(loop) finally: loop.set_debug(True) return loop async def _receive_via_aiohttp(self, session, url, headers): async with session.get(url, headers=headers) as response: content = await response.read() return response, content async def _fetch(self, url, session): headers = {'User-Agent': 'MyAgent'} # use aiohttp to get feed/xml content and response object response, content = await self._receive_via_aiohttp(session, url, headers) # do a lot more stuff... def run(self): loop = self._get_loop() asyncio.run(self._run_async()) loop.close() async def _run_async(self): async with aiohttp.ClientSession() as session: # in real there are much more URLs urls = ['https://cnn.com', 'https://fsfe.org'] # create the "jobs" (futures) futures = [self._fetch(url, session) for url in urls] # run the "jobs" asynchrone self._get_loop().run_until_complete(asyncio.wait(futures)) if __name__ == '__main__': obj = FetchAsync() obj.run() And this is the full error output
Traceback (most recent call last): File "/home/user/share/work/aiotest/./fetchfeeds.py", line 62, in <module> obj.run() File "/home/user/share/work/aiotest/./fetchfeeds.py", line 43, in run asyncio.run(self._run_async()) File "/usr/lib/python3.9/asyncio/runners.py", line 44, in run return loop.run_until_complete(main) File "/usr/lib/python3.9/asyncio/base_events.py", line 642, in run_until_complete return future.result() File "/home/user/share/work/aiotest/./fetchfeeds.py", line 58, in _run_async self._get_loop().run_until_complete(asyncio.wait(futures)) File "/usr/lib/python3.9/asyncio/base_events.py", line 618, in run_until_complete self._check_running() File "/usr/lib/python3.9/asyncio/base_events.py", line 578, in _check_running raise RuntimeError('This event loop is already running') RuntimeError: This event loop is already running sys:1: RuntimeWarning: coroutine 'wait' was never awaited sys:1: RuntimeWarning: coroutine 'FetchAsync._fetch' was never awaited 
