属性错误：“非类型”对象在运行Flask时没有属性“app”

Question

我正试图触发我的flask代码以几分钟的间隔作为计划作业运行。该应用程序主要对来自多个站点的新闻进行Web垃圾处理，并将其显示为HTML网页

当我使用apscheduler调度我的Flask函数时，我开始得到以下错误：

Job "news_page (trigger: interval[0:02:00], next run at: 2020-03-11 17:54:32 IST)" raised an exception
Traceback (most recent call last):
File "C:\Users\poudupa\PycharmProjects\SecNews\venv\lib\site-packages\apscheduler\executors\base.py", line 125, in run_job
retval = job.func(*job.args, **job.kwargs)
File "C:\Users\poudupa\PycharmProjects\SecNews\venv\Scripts\try_flask.py", line 20, in news_page
return render_template('news_screen.html', hackernews = hackernews, bcnews = bcnews, tpnews = tpnews, nsnews = nsnews, drnews = drnews, wsnews = wsnews)
File "C:\Users\poudupa\PycharmProjects\SecNews\venv\lib\site-packages\flask\templating.py", line 136, in render_template
ctx.app.update_template_context(context)
AttributeError: 'NoneType' object has no attribute 'app'

这是我的代码：

from flask import Flask, request, render_template
from pullnews import *
from apscheduler.schedulers.background import BackgroundScheduler
import datetime

app = Flask(__name__)
app.debug=True

class Item:
    def __init__(self, vals):
        self.__dict__ = vals

@app.route('/')
def news_page():
    hackernews = get_hackernews()
    bcnews = get_bcnews()
    tpnews = get_threatpost()
    nsnews = get_nakedsecurity()
    drnews = get_darkreading()
    wsnews = get_welivesecurity()
    return render_template('news_screen.html', hackernews = hackernews, bcnews = bcnews, tpnews = tpnews, nsnews = nsnews, drnews = drnews, wsnews = wsnews)

sched = BackgroundScheduler(daemon=True)
sched.add_job(news_page, 'interval', minutes=2)
sched.start()


if __name__ == '__main__':
    app.run()

如何解决此错误？当我在没有调度程序作业的情况下手动运行Flask代码时，不会发生这种情况