python - Try-Catch Exception 在 OpenCV-python 中不起作用

Question

所以我特意在 cv2.VideoCapture() 中放置了一个文件，该文件在我的计算机中不存在以测试我已放入代码中的 try-catch 系统，但由于某种原因，它仍然会发出与我相同的错误没有将 try-catch 放入我的代码中。我该如何解决？？
代码:

import numpy as np
import cv2



try:
    cap = cv2.VideoCapture('trial.mkv')
    while (cap.isOpened()):
        ret, frame = cap.read()

        cv2.imshow('frame', frame)
        if cv2.waitKey(1) & 0xFF == ord('q'):
            break

    cap.release()
    cv2.destroyAllWindows()
except:
    print("no file found")

错误:

[ERROR:0] global C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-cff9bdsm\opencv\modules\videoio\src\cap.cpp (142) cv::VideoCapture::open VIDEOIO(CV_IMAGES): raised OpenCV exception:

OpenCV(4.4.0) C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-cff9bdsm\opencv\modules\videoio\src\cap_images.cpp:253: error: (-5:Bad argument) CAP_IMAGES: can't find starting number (in the name of file): trial.mkv in function 'cv::icvExtractPattern'

Answer 1

当 try/except 捕获到错误时声明和 stderr msg 仍然被打印，这只是意味着库只是将所有错误消息发送到 stderr .OpenCV众所周知，图书馆有这个问题，并且有办法解决它。你应该在这里阅读详细的答案 - OpenCv error和 How to stop OpenCV error message from printing in Python