我試圖加載一個YouTube視頻，在臉上放一個盒子，并預測他們的年齡和性別。但是，當我運行代碼時，它只是執行，但彈出窗口沒有出現。我的代碼在下面。我不確定問題出在哪里。感謝您的幫助，伙計們import pafyimport cv2url = 'https://www.youtube.com/watch?v=dTL7LriRZJQ'    #URL that you want to copyvPafy= pafy.new(url) #get URL and get best mp4 video play = vPafy.getbest(preftype="mp4")#Video capturecap = cv2.VideoCapture(play.url) MODEL_MEAN_VALUES = (78.4, 87.7, 114.9)age_list = ['(0, 2)', '(4, 6)', '(8, 12)', '(15, 20)', '(25, 32)', '(38, 43)', '(48, 53)', '(60, 100)']gender_list = ['Male', 'Female']# defining a function to load prototxt & caffe def init_caffe_models():    age_net = cv2.dnn.readNetFromCaffe('/Users/Desktop/Gender-and-Age-Detection-master/age_deploy.prototxt', '/Users/Desktop/Gender-and-Age-Detection-master/age_net.caffemodel')    gender_net = cv2.dnn.readNetFromCaffe('/Users/Desktop/Gender-and-Age-Detection-master/gender_deploy.prototxt','/Users/Desktop/Gender-and-Age-Detection-master/gender_net.caffemodel')    return(age_net, gender_net)# defining a function for capturing the videodef video_detector(age_net, gender_net):    font = cv2.FONT_HERSHEY_SIMPLE    while True:        ret, frame = cap.read()     #returns a boolean            gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)        face_cascade = cv2.CascadeClassifier('/Users/Desktop/OpenCV-Python-Series-master/src/cascades/data/haarcascade_frontalface_default.xml')        faces = face_cascade.detectMultiScale(gray, 1.1, 5) # input = grey image, 1.1 = scale factor