aiohttp RuntimeError: await wasn't used with future

Question

我知道，但是那里的答案没有解决这里发生的事情。

使用aiohttp时我运行出现以下错误：

  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/asyncio/selector_events.py", line 485, in sock_connect
    return await fut
RuntimeError: await wasn't used with future
Unclosed client session
client_session: <aiohttp.client.ClientSession object at 0x7fb28040f760>

这是关联的代码：

urls = # some list of URLs including `https://www.alphavantage.co/query?function=OVERVIEW&symbol=IBM&apikey=demo`.....

async def run_tasks():
    session = aiohttp.ClientSession()
    tasks = [session.get(url) for url in urls]
    await asyncio.gather(*tasks)
    await session.close()

asyncio.run(run_tasks())

看起来我正在正确等待事件循环，但我一直遇到这个问题，这是怎么回事？

版本：

aiohttp==3.7.4.post0
asyncio==3.4.3
Python 3.8.0

Answer 1

这里可能会发生两件事：

你没有await做你应该做的事情
您调用的 URL 是错误的请求，并且在您有机会查看实际情况之前事件循环出错。

根据 aiohttp documentation

By default aiohttp uses strict checks for HTTPS protocol. Certification checks can be relaxed by setting ssl to False

所以您使用的 urls 很可能达到了这个阈值，您将被踢出。更改行：

tasks = [session.get(url) for url in urls]

到

tasks = [session.get(url, ssl=False) for url in urls]

Answer 2

我知道这不能直接回答您的问题，但 aiohttp request life-cycle 中实际上有一些异步调用，所以您必须在几个地方 await ：

import asyncio

import aiohttp

URL = "https://whosebug.com"


async def main():
    session = aiohttp.ClientSession()
    resp = await session.get(URL)
    html = await resp.text()

    print(f"{URL} <{resp.status}> ({len(html)})")

    resp.release()

    await session.close()


if __name__ == "__main__":
    asyncio.run(main())

通常且更简单的方法是使用 context managers 以确保正确关闭所有剩余资源：

import asyncio

import aiohttp

URLS = [
    "https://serverfault.com",
    "https://whosebug.com",
]


async def fetch(session, url):
    async with session.get(url) as resp:
        html = await resp.text()

        print(f"{url} <{resp.status}>")

    return {url: len(html)}


async def main():
    tasks = []

    async with aiohttp.ClientSession() as session:
        for url in URLS:
            tasks.append(asyncio.create_task(fetch(session, url)))

        data = await asyncio.gather(*tasks)

    print(data)


if __name__ == "__main__":
    asyncio.run(main())

测试：

$ python test.py
https://serverfault.com <200>
https://whosebug.com <200>
[{'https://serverfault.com': 143272}, {'https://whosebug.com': 191046}]

aiohttp RuntimeError: await wasn't used with future

aiohttp RuntimeError: await wasn't used with future

python

python-asyncio

aiohttp