切片数组时出现“ TypeError：'NoneType'对象无法下标”

Question

    cap = cv2.VideoCapture(video_path)
    ret , prev_frame = cap.read()
    count = 0
    while ret:
        ret , curr_frame = cap.read()
        a1 = curr_frame[:int(h/2-1),:int(w/2-1)]

错误：

a1 = curr_frame[:int(h/2-1), :int(w/2-1)]
TypeError: 'NoneType' object is not subscriptable

Answer 1

您可能要测试您的cap.read（）语句。很明显，它返回了none结果。

cap = cv2.VideoCapture(video_path)
    ret , prev_frame = cap.read()
    count = 0
    while ret:
        ret , curr_frame = cap.read() or []
        a1 = curr_frame[:int(h/2-1),:int(w/2-1)]