Python, async, strange error after code is finished: Event loop is closed Process finished with exit code 0

Question

What is wrong with this code? I tried to close loop manually by many ways, but all them failed. Enviroment: windows 10. Running via pycharm (venv) and powershell/python (both failed).

async def load_page(url: str, session):
    async with session.get(url=url) as resp:
        if 200 <= resp.status <= 299:
            return await resp.text()


async def main():
    async with aiohttp.ClientSession() as session:
        pages = []
        for shift in range(0, 2000, 200):  # Pagination
            url = f'http://example.com?param={shift}'
            pages.append(load_page(url=url, session=session))
        return await asyncio.gather(*pages)


if __name__ == '__main__':
    print(asyncio.run(main()))

Error:

RuntimeError: Event loop is closed

Process finished with exit code 0

Full error:

Exception ignored in: <function _ProactorBasePipeTransport.__del__ at 0x00000204B17CBCA0>
Traceback (most recent call last):
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 116, in __del__
    self.close()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 108, in close
    self._loop.call_soon(self._call_connection_lost, None)
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 746, in call_soon
    self._check_closed()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 510, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed
Exception ignored in: <function _ProactorBasePipeTransport.__del__ at 0x00000204B17CBCA0>
Traceback (most recent call last):
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 116, in __del__
    self.close()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 108, in close
    self._loop.call_soon(self._call_connection_lost, None)
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 746, in call_soon
    self._check_closed()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 510, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed
Exception ignored in: <function _ProactorBasePipeTransport.__del__ at 0x00000204B17CBCA0>
Traceback (most recent call last):
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 116, in __del__
    self.close()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 108, in close
    self._loop.call_soon(self._call_connection_lost, None)
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 746, in call_soon
    self._check_closed()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 510, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed
Exception ignored in: <function _ProactorBasePipeTransport.__del__ at 0x00000204B17CBCA0>
Traceback (most recent call last):
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 116, in __del__
    self.close()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 108, in close
    self._loop.call_soon(self._call_connection_lost, None)
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 746, in call_soon
    self._check_closed()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 510, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed
Exception ignored in: <function _ProactorBasePipeTransport.__del__ at 0x00000204B17CBCA0>
Traceback (most recent call last):
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 116, in __del__
    self.close()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 108, in close
    self._loop.call_soon(self._call_connection_lost, None)
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 746, in call_soon
    self._check_closed()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 510, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed
Exception ignored in: <function _ProactorBasePipeTransport.__del__ at 0x00000204B17CBCA0>
Traceback (most recent call last):
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 116, in __del__
    self.close()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 108, in close
    self._loop.call_soon(self._call_connection_lost, None)
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 746, in call_soon
    self._check_closed()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 510, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed
Exception ignored in: <function _ProactorBasePipeTransport.__del__ at 0x00000204B17CBCA0>
Traceback (most recent call last):
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 116, in __del__
    self.close()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 108, in close
    self._loop.call_soon(self._call_connection_lost, None)
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 746, in call_soon
    self._check_closed()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 510, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed
Exception ignored in: <function _ProactorBasePipeTransport.__del__ at 0x00000204B17CBCA0>
Traceback (most recent call last):
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 116, in __del__
    self.close()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 108, in close
    self._loop.call_soon(self._call_connection_lost, None)
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 746, in call_soon
    self._check_closed()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 510, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed
Exception ignored in: <function _ProactorBasePipeTransport.__del__ at 0x00000204B17CBCA0>
Traceback (most recent call last):
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 116, in __del__
    self.close()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 108, in close
    self._loop.call_soon(self._call_connection_lost, None)
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 746, in call_soon
    self._check_closed()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 510, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed
Exception ignored in: <function _ProactorBasePipeTransport.__del__ at 0x00000204B17CBCA0>
Traceback (most recent call last):
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 116, in __del__
    self.close()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 108, in close
    self._loop.call_soon(self._call_connection_lost, None)
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 746, in call_soon
    self._check_closed()
  File "C:\Users\david\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 510, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed

Process finished with exit code 0

it seems to be working as expected for me on Unix environment. could you add how are you executing this code? I have observed scripts involving `asyncio` not running correctly with `Spyder` and I have to clear the variables to make it work for different iterations. — Krishna Chaurasia, Mar 16 '21 at 12:57
You could have a look at the similar thread: https://stackoverflow.com/questions/59255332/exception-event-loop-is-closed-with-aiohttp-and-asyncio-in-python-3-8 — Krishna Chaurasia, Mar 16 '21 at 15:44
@KrishnaChaurasia Thanks, this is an answer, you can post him, I will accept it — kukuruza, Mar 16 '21 at 16:44

Python, async, strange error after code is finished: Event loop is closed Process finished with exit code 0

0 Answers0