Python - 用 yield 停止无限循环，然后重定向

Question

我试图停止一个无限的 while 循环，该循环使用 yield 函数从相机馈送中传递帧，但如果在识别过程中在相机中识别了正确的人，还会传递一个确认标签（“确认”）。 所以我写了一个 if 语句，检查确认不等于“notfound”，如果是这样，它意味着它是一个人，我需要重定向到某个地方，在这个例子中 - 主页。

from flask import Flask, render_template, Response, redirect, url_for
import cv2
import numpy as np
from camera2 import VideoCamera

app = Flask(__name__)

light_on = False

@app.route('/', methods=['GET', 'POST'])
@app.route('/home', methods=['GET', 'POST'])

def home():
    return render_template("main.html")

@app.route('/recognition', methods=['GET', 'POST'])
def recognition():
    return render_template('recognition.html')

def gen(camera2):
    while True:
        confirmation, frame = camera2.get_frame()
        print(confirmation)
        # yield ('--frame\r\nContent-Type: image/jpeg\r\n\r\n' + frame + '\r\n\r\n')
        yield (b'--frame\r\n'
               b'Content-Type: image/jpeg\r\n\r\n' + frame + b'\r\n\r\n')
        if confirmation != "notfound":
            return redirect(url_for("home")) 

@app.route('/video_feed')
def video_feed():
    return Response(gen(VideoCamera()),
                    mimetype='multipart/x-mixed-replace; boundary=frame')

if __name__ == '__main__':
    app.run("localhost", 5050, debug=True, threaded=True)

但是每当我尝试这样做时，我都会收到一条错误消息：

"Attempted to generate a URL without the application context being"
RuntimeError: Attempted to generate a URL without the application context being pushed. This has to be executed when application context is available.

我将不胜感激任何帮助或建议！

谢谢！

Answer 1

我遇到了类似的问题，这可能对某人有所帮助...

from functools import wraps

def my_decorator(function):    
    @wraps(function)
    def wrapper():
        if not os.path.isdir(audioPath):
            return ""
        return function()
    return wrapper

@app.route('/playaudio')
@my_decorator           # this avoid infinity loop
def playaudio():
    def generate():
        data = ""
        if os.path.isdir(audioPath):
            for audioPath in filesAudios:
                data=subprocess.check_output(['cat',audioPath])
                yield data      # ifinity loop if audioPath do not exist
        return data
    return Response(generate(), mimetype='audio/mp3')