Question

我正在制作一个简单的flask应用程序，该应用程序从外部网站返回结果。用户将数据输入我的站点。此数据用于加载另一个站点。提取数据并以列表形式返回。该程序可独立运行，但不能作为flask应用程序的一部分运行。我尝试使用它的异步工具来使用requests_HTML库，并且尝试使用Pyro4将请求发送到外部进程。但是我总是想出这个错误的一些版本：

RunTimeError：线程........

中没有当前事件循环

在我看来，当我导入的模块之一运行线程时，Flask不喜欢它。我想知道为什么会发生这种情况，它们是否在烧瓶内部起作用，这意味着它不能与线程或异步或某些东西一起很好地工作？指向一些额外资源或信息的任何方向将非常感谢

这是我的Flask应用程序：

from flask import Flask, render_template
from requests_html import AsyncHTMLSession

app = Flask(__name__)
asession = AsyncHTMLSession()
URLS=["https://stackoverflow.com/questions/",
      "https://stackoverflow.com/questions/",
      "https://stackoverflow.com/questions/"]

@app.route("/", methods=('GET'))
def index():
results = asession.run(run_requests)
return render_template('index_page.html', results_list=results)

async def run_requests():
    results_list=[]
    for url in URLS:
        results_list.append(await get_and_render(url))
    return results_list

async def get_and_render(url):
    r = await asession.get(url)
    await r.html.arender(sleep=0.75)
    summary = r.html.find(".question-hyperlink", first=True)
    return summary.text

这将显示stackoverflow问题页面，并获取最后发布的问题的摘要。我已经在独立的python文件中尝试过此代码，并且可以正常工作。（即在flask应用程序外部，只需将结果打印到命令行即可）

这是通过烧瓶调试器进行的追溯：

'Traceback (most recent call last):
 File "C:\Users\Alex\AppData\Local\Programs\Python\Python38-32\Lib\site-packages\flask\app.py", line 2463, in __call__
 return self.wsgi_app(environ, start_response)
 File "C:\Users\Alex\AppData\Local\Programs\Python\Python38-32\Lib\site-packages\flask\app.py", line 2449, in wsgi_app
 response = self.handle_exception(e)
 File "C:\Users\Alex\AppData\Local\Programs\Python\Python38-32\Lib\site-packages\flask\app.py", line 1866, in handle_exception
 reraise(exc_type, exc_value, tb)
 File "C:\Users\Alex\AppData\Local\Programs\Python\Python38-32\Lib\site-packages\flask\_compat.py", line 39, in reraise
 raise value
 File "C:\Users\Alex\AppData\Local\Programs\Python\Python38-32\Lib\site-packages\flask\app.py", line 2446, in wsgi_app
 response = self.full_dispatch_request()
 File "C:\Users\Alex\AppData\Local\Programs\Python\Python38-32\Lib\site-packages\flask\app.py", line 1951, in full_dispatch_request
 rv = self.handle_user_exception(e)
 File "C:\Users\Alex\AppData\Local\Programs\Python\Python38-32\Lib\site-packages\flask\app.py", line 1820, in handle_user_exception
 reraise(exc_type, exc_value, tb)
 File "C:\Users\Alex\AppData\Local\Programs\Python\Python38-32\Lib\site-packages\flask\_compat.py", line 39, in reraise
 raise value
 File "C:\Users\Alex\AppData\Local\Programs\Python\Python38-32\Lib\site-packages\flask\app.py", line 1949, in full_dispatch_request
 rv = self.dispatch_request()
 File "C:\Users\Alex\AppData\Local\Programs\Python\Python38-32\Lib\site-packages\flask\app.py", line 1935, in dispatch_request
 return self.view_functions[rule.endpoint](**req.view_args)
 File "C:\......\StackOverflowExample.py", line 11, in index
 results = asession.run(run_requests)
 File "C:\Users\Alex\AppData\Local\Programs\Python\Python38-32\Lib\site-packages\requests_html.py", line 771, in run
 tasks = [
 File "C:\Users\Alex\AppData\Local\Programs\Python\Python38-32\Lib\site-packages\requests_html.py", line 772, in <listcomp>
 asyncio.ensure_future(coro()) for coro in coros
 File "C:\Users\Alex\AppData\Local\Programs\Python\Python38-32\Lib\asyncio\tasks.py", line 660, in ensure_future
 loop = events.get_event_loop()
 File "C:\Users\Alex\AppData\Local\Programs\Python\Python38-32\Lib\asyncio\events.py", line 639, in get_event_loop
 raise RuntimeError('There is no current event loop in thread %r.'
 RuntimeError: There is no current event loop in thread 'Thread-4'.

谁能解释为什么烧瓶在完成这些任务时遇到麻烦？

欢呼

PS 这是我的简单HTML（尽管应用程序尚无法呈现它。）：

        <ul>
            {% for result in results_list %}
            <li>{{result}}</li>
            {% endfor %}
        </ul>

这是我的烧瓶应用程序外部的脚本（有效）：

from requests_html import AsyncHTMLSession
asession = AsyncHTMLSession()
URLS=["https://stackoverflow.com/questions/",
  "https://stackoverflow.com/questions/",
  "https://stackoverflow.com/questions/"]

def index():
    results = asession.run(run_requests)
    for result in results:
        print(result)

async def run_requests():
    results_list=[]
    for url in URLS:
        results_list.append(await get_and_render(url))
    return results_list

async def get_and_render(url):

    r = await asession.get(url)
    await r.html.arender(sleep=0.75)
    summary = r.html.find(".question-hyperlink", first=True)
    print(summary.text)

if __name__ == "__main__":
    index()

烧瓶：RunTimeError：线程

0 个答案: