python - TypeError : An asyncio. Future，需要协程或等待

Question

我正在尝试使用 beautifulsoup 和 aiohttp 制作一个异步网络抓取工具。这是我开始工作的初始代码。我收到一个 [TypeError: An asyncio.Future, a coroutine or an waitable is required] 并有很难找出我的代码出了什么问题。我是 python 新手，非常感谢任何有关此问题的帮助。

import bs4
import asyncio
import aiohttp


async def parse(page):
    soup=bs4.BeautifulSoup(page,'html.parser')
    soup.prettify()
    print(soup.title)



async def request():
    async with aiohttp.ClientSession() as session:
        async with session.get("https://google.com") as resp:
            await parse(resp)



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

回溯:-

Traceback (most recent call last):
  File "C:\Users\User\Desktop\Bot\aio-req\parser.py", line 21, in <module>
    loop.run_until_complete(request)
  File "C:\Users\User\AppData\Local\Programs\Python\Python38-32\lib\asyncio\base_events.py", line 591, in run_until_complete
    future = tasks.ensure_future(future, loop=self)
  File "C:\Users\User\AppData\Local\Programs\Python\Python38-32\lib\asyncio\tasks.py", line 673, in ensure_future
    raise TypeError('An asyncio.Future, a coroutine or an awaitable is '
TypeError: An asyncio.Future, a coroutine or an awaitable is required

Answer 1

一个问题是 loop.run_until_complete(request) 应该是 loop.run_until_complete(request()) - 您实际上必须调用它才能返回协程。

还有更多问题 - 比如您将 aiohttp.ClientResponse 对象传递给 parse 并将其视为文本/html。我让它可以与以下内容一起使用，但不知道它是否适合您的需求，因为 parse 不再是协程。

def parse(page):
    soup=bs4.BeautifulSoup(page,'html.parser')
    soup.prettify()
    return soup.title

async def fetch(session, url):
    async with session.get(url) as response:
        return await response.text()

async def request():
    async with aiohttp.ClientSession() as session:
        html = await fetch(session, "https://google.com")
        print(parse(html))

if __name__ == '__main__':
    loop=asyncio.get_event_loop()
    loop.run_until_complete(request())

<小时/>

这也有效:

def parse(page):
    soup=bs4.BeautifulSoup(page,'html.parser')
    soup.prettify()
    print(soup.title)

async def request():
    async with aiohttp.ClientSession() as session:
        async with session.get("https://google.com") as resp:
            parse(await resp.text())

<小时/>

最后，您的原始代码，将可等待的响应对象传递给 parse，然后等待 page.text()。

async def parse(page):
    soup=bs4.BeautifulSoup(await page.text(),'html.parser')
    soup.prettify()
    print(soup.title)

async def request():
    async with aiohttp.ClientSession() as session:
        async with session.get("https://google.com") as resp:
            await parse(resp)