count = 1for i in real_videonames_index: videofile = filed[i] success = True vidcap = cv2.VideoCapture(videofile) while success: if (count%one_frame_each == 0): success,image = vidcap.read() image_gray = rgb2gray(image) if image.shape[1]>640: tmp = resize(image_gray,(math.floor(640 / image_gray.shape[1] * image_gray.shape[0]), 640),mode='constant') name = '/content/drive/MyDrive/Training/REAL/' + str(count) + '.jpg' print('正在创建 ....' + name) cv2.imwrite(name, image) print ('*', end="") else: success,image = vidcap.read() count += 1 print('/n/n/n/n第{}个视频已成功完成/n/n/n'.format(i)) i += 1在简单的迭代循环中工作正常，但在提取帧时仅对前三个索引有效？
捕获第一个视频帧后的错误如下。
我在使用Google Colab。提前感谢。
回答：
实际上，错误出现在最后一个帧cv2获取了None值，因此可以通过再次获取帧来解决。正确的代码如下：
count = 0face_cascade = cv2.CascadeClassifier('/content/drive/MyDrive/Training/haarcascade_frontalface_default.xml')for i in real_videonames_index[51:76]: videofile = videonames_list[i] vidcap = cv2.VideoCapture(videofile) success,image = vidcap.read() while success: if (count%one_frame_each == 0): name = '/content/drive/MyDrive/Training/Validation Data/REAL/'+names[i]+ "_" + str(count) + '.jpg' image = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY) facesBase = face_cascade.detectMultiScale(image, scaleFactor=1.1, minNeighbors=5) for f in facesBase: x, y, w, h = [ v for v in f ] cv2.rectangle(image, (x,y), (x+w, y+h), (255,0,0), 3) face_crop = image[y:y+h, x:x+w] cv2.imwrite(name, face_crop) success,image = vidcap.read() print('读取新帧: {} 并命名为 {}'.format(success,count)) else: success,image = vidcap.read() print('读取新帧: {} 并命名为 {}'.format(success,count)) count += 1 print('第{}个真实视频已成功提取'.format(i)) i += 1