python-2.7 - 属性错误 : 'NoneType' object has no attribute 'tostring'

Question

所以前几天刚开始编程，遇到了这个问题:AttributeError: 'NoneType' object has no attribute 'tostring' .我不知道出了什么问题。

#Reads through each frame, calculates the timestamp, places it on the frame and
#exports the frame to the output video.
while current_frame < total_frames:
    success, image = video.read()
    elapsed_time = video.get(cv2.CAP_PROP_POS_MSEC)
    current_frame = video.get(cv2.CAP_PROP_POS_FRAMES)
    timestamp = initial + dt.timedelta(microseconds = elapsed_time*1000)
    cv2.putText(image, 'Date: ' + str(timestamp)[0:10], (50,int(height-150)), cv2.FONT_HERSHEY_COMPLEX_SMALL, 2, (255, 255, 255), 3)
    cv2.putText(image, 'Time: ' + str(timestamp)[11:-4], (50,int(height-100)), cv2.FONT_HERSHEY_COMPLEX_SMALL, 2, (255, 255, 255), 3)
    pipe.stdin.write(image.tostring())

Answer 1

可能某些帧没有正确返回，因此 image变量为空，因此为 NoneType ，即它没有类型。

使用 image.shape 检查图像的形状.

您还可以使用 type(variable) 检查 Python 中任何变量的类型。 .
if image.shape[0]==0 or image.shape[1]==0:
continue #or do something else to handle this