为什么出现错误“无法在现有事件循环中使用HTMLSession请改用AsyncHTMLSession”？

问题描述

我正在运行@ Dan-Dev在他的answer中提供的代码。

from requests_html import HTMLSession

url = 'https://www.thefreedictionary.com/love'
session = HTMLSession()
r = session.get(url)
r.html.render()
lang_bar = r.html.find('#LangBar',first=True)
print(lang_bar.html)

结果是

---------------------------------------------------------------------------
RuntimeError                              Traceback (most recent call last)
<ipython-input-2-ec1d9137b197> in <module>
      8 
      9 resp = session.get(url,headers = headers)
---> 10 resp.html.render()
     11 
     12 soup = bs(resp.html.html,"lxml")

C:\Anaconda3\lib\site-packages\requests_html.py in render(self,retries,script,wait,scrolldown,sleep,reload,timeout,keep_page)
    584         """
    585 
--> 586         self.browser = self.session.browser  # Automatically create a event loop and browser
    587         content = None
    588 

C:\Anaconda3\lib\site-packages\requests_html.py in browser(self)
    727             self.loop = asyncio.get_event_loop()
    728             if self.loop.is_running():
--> 729                 raise RuntimeError("Cannot use HTMLSession within an existing event loop. Use AsyncHTMLSession instead.")
    730             self._browser = self.loop.run_until_complete(super().browser)
    731         return self._browser

RuntimeError: Cannot use HTMLSession within an existing event loop. Use AsyncHTMLSession instead.

很显然，该代码在Dan-Dev的计算机上运行良好。您能否解释为什么我的笔记本电脑返回错误Cannot use HTMLSession within an existing event loop. Use AsyncHTMLSession instead？

解决方法

您可以尝试以下方法：

import nest_asyncio

nest_asyncio.apply()

session = HTMLSession()
r = session.get(url_template.format(url))

html_str = r.text