[未解決問題記錄]python asyncio+aiohttp出現Exception ignored：RuntimeError('Event loop is closed')

找了半天沒找到原因，記錄一下

操作系統：windows 8.1

python版本：python 3.8.1

aiohttp版本：3.6.2

源碼：

import asyncio
import aiohttp


async def aiohttp_request_test(url):
    async with aiohttp.request('get', url=url) as resp:
        await resp.text()
        # await asyncio.sleep(1) # A1


async def main():
    await asyncio.gather(aiohttp_request_test('https://www.baidu.com'))


asyncio.run(main())
# loop = asyncio.get_event_loop()
# loop.run_until_complete(main())

運行以上代碼時，出現如下異常：

Exception ignored in: <function _ProactorBasePipeTransport.__del__ at 0x02A8C8E0>
Traceback (most recent call last):
  File "D:\Python\Anaconda3\envs\python38\lib\asyncio\proactor_events.py", line 116, in __del__
    self.close()
  File "D:\Python\Anaconda3\envs\python38\lib\asyncio\proactor_events.py", line 108, in close
    self._loop.call_soon(self._call_connection_lost, None)
  File "D:\Python\Anaconda3\envs\python38\lib\asyncio\base_events.py", line 715, in call_soon
    self._check_closed()
  File "D:\Python\Anaconda3\envs\python38\lib\asyncio\base_events.py", line 508, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed

但是在第8行處加上一句await asyncio.sleep(1)后，無異常（方案A）

或者將

asyncio.run(main())

改為：

loop = asyncio.get_event_loop()
loop.run_until_complete(main())

也無異常。（方案B）

（實際使用的時候方案B也會出現上述異常，但這里未能復現，且也可用方案A解決）

我就很奇怪為什么加上一句await asyncio.sleep(1)就不報錯了

還有，如果request拋出了一個異常並被捕獲的話（將aiohttp_request_test改為如下）：

async def aiohttp_request_test(url):
    try:
        async with aiohttp.request('get', url=url) as resp:
            await resp.text()
    except:
        pass

則也不會報RuntimeError: Event loop is closed

 

困了，找到原因了再回來補充。

-----------------------------------------------------------分割線-----------------------------------------------------------

在aiohttp官方文檔找到一個疑似的原因：https://docs.aiohttp.org/en/latest/client_advanced.html#graceful-shutdown