使用 http 代理的 aiohttp https 请求失败

Question

我正在构建一个测试项目来学习 asyncio。我正在构建一个通过代理服务器获取多个页面的程序。

它对于 http 页面工作正常，但对于 https 页面则失败。当我使用常规请求库时，我也可以使用 https 页面，但不能使用 asyncio。

我隔离了损坏的代码：

import aiohttp
import asyncio

async def fetch(url):
    async with aiohttp.ClientSession() as session:
        async with session.get(url, proxy="http://192.168.0.2:9001") as response:
            print(await response.text())

loop = asyncio.get_event_loop()
loop.run_until_complete(fetch("https://google.com")) #http websites do work

错误：

Traceback (most recent call last):
  File "C:\Users\GG\AppData\Local\Programs\Python\Python38-32\lib\site-packages\aiohttp\connector.py", line 936, in _wrap_create_connection
    return await self._loop.create_connection(*args, **kwargs)  # type: ignore  # noqa
  File "C:\Users\GG\AppData\Local\Programs\Python\Python38-32\lib\asyncio\base_events.py", line 1050, in create_connection
    transport, protocol = await self._create_connection_transport(
  File "C:\Users\GG\AppData\Local\Programs\Python\Python38-32\lib\asyncio\base_events.py", line 1080, in _create_connection_transport
    await waiter
  File "C:\Users\GG\AppData\Local\Programs\Python\Python38-32\lib\asyncio\proactor_events.py", line 395, in _loop_writing
    self._write_fut = self._loop._proactor.send(self._sock, data)
  File "C:\Users\GG\AppData\Local\Programs\Python\Python38-32\lib\asyncio\windows_events.py", line 525, in send
    self._register_with_iocp(conn)
  File "C:\Users\GG\AppData\Local\Programs\Python\Python38-32\lib\asyncio\windows_events.py", line 714, in _register_with_iocp
    _overlapped.CreateIoCompletionPort(obj.fileno(), self._iocp, 0, 0)
OSError: [WinError 87] The parameter is incorrect

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:/data/Python/playground/sayncio_session.py", line 10, in <module>
    loop.run_until_complete(fetch("https://google.com")) #http websites do work
  File "C:\Users\GG\AppData\Local\Programs\Python\Python38-32\lib\asyncio\base_events.py", line 616, in run_until_complete
    return future.result()
  File "C:/data/Python/playground/sayncio_session.py", line 6, in fetch
    async with session.get(url, proxy="http://192.168.0.2:9001") as response:
  File "C:\Users\GG\AppData\Local\Programs\Python\Python38-32\lib\site-packages\aiohttp\client.py", line 1012, in __aenter__
    self._resp = await self._coro
  File "C:\Users\GG\AppData\Local\Programs\Python\Python38-32\lib\site-packages\aiohttp\client.py", line 480, in _request
    conn = await self._connector.connect(
  File "C:\Users\GG\AppData\Local\Programs\Python\Python38-32\lib\site-packages\aiohttp\connector.py", line 523, in connect
    proto = await self._create_connection(req, traces, timeout)
  File "C:\Users\GG\AppData\Local\Programs\Python\Python38-32\lib\site-packages\aiohttp\connector.py", line 855, in _create_connection
    _, proto = await self._create_proxy_connection(
  File "C:\Users\GG\AppData\Local\Programs\Python\Python38-32\lib\site-packages\aiohttp\connector.py", line 1093, in _create_proxy_connection
    transport, proto = await self._wrap_create_connection(
  File "C:\Users\GG\AppData\Local\Programs\Python\Python38-32\lib\site-packages\aiohttp\connector.py", line 943, in _wrap_create_connection
    raise client_error(req.connection_key, exc) from exc
aiohttp.client_exceptions.ClientConnectorError: Cannot connect to host google.com:443 ssl:default [The parameter is incorrect]

Process finished with exit code 1

我正在使用 aiohttp=3.6.2 和 python=3.8.2

我该如何修复这个错误？

Answer 1

我aiohttp在 Windows 上尝试使用ProactorEventLoop. 从 Python 3.8 开始，它现在是 Windows 上的默认事件循环（而不是SelectorEventLoop），因此在库得到修复之前，解决方法是SelectorEventLoop显式切换回：

import aiohttp
import asyncio

async def fetch(url):
    ...

asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())

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

相关：的跟踪器中的问题#2245 。aiohttp