Question

我正在编写一个帮助程序类，以异步方式处理多个url请求。代码如下。

class urlAsyncClient(object):
    def  __init__(self, url_arr):
        self.url_arr = url_arr

    async def async_worker(self):
        result = await self.__run()
        return result

    async def __run(self):
        pending_req = []
        async with aiohttp.ClientSession() as session:
            for url in self.url_arr:
                r = self.__fetch(session, url)
                pending_req.append(r)
        #Awaiting the results altogether instead of one by one
        result = await asyncio.wait(pending_req)
        return result

    @staticmethod
    async def __fetch(session, url):
        async with session.get(url) as response: #ERROR here
            status_code = response.status
            if status_code == 200:
                return await response.json()
            else:
                result = await response.text()
                print('Error ' + str(response.status_code) + ': ' + result)
                return {"error": result}

等待结果一个接一个的异步似乎没有意义。我将它们放入一个数组中，然后await asyncio.wait(pending_req)一起等待。

但是当我遇到以下错误时，这似乎不是正确的方法

在__fetch异步中，使用session.get（url）作为响应：RuntimeError：会话已关闭

我可以知道正确的方法吗？谢谢。

Answer 1

因为会话在您等待之前已经关闭

  async with aiohttp.ClientSession() as session:
        for url in self.url_arr:
            r = self.__fetch(session, url)
            pending_req.append(r)
  #session closed hear

您可以像这样将会话设为__run的参数

async def async_worker(self):
    async with aiohttp.ClientSession() as session:
        result = await self.__run(session)
        return result
    # session will close hear

async def __run(self, session):
    pending_req = []
    for url in self.url_arr:
        r = self.__fetch(session, url)
        pending_req.append(r)
    #Awaiting the results altogether instead of one by one
    result = await asyncio.wait(pending_req)
    return result

等待多个aiohttp请求导致“会话已关闭”错误

1 个答案: