pip install opencv-python
pip install opencv-contrib-python

Installing collected packages: opencv-contrib-python
Could not install packages due to an EnvironmentError: [WinError 5] 拒绝访问。: 'c:\\users\\water\\appdata\\local\\programs\\python\\python37\\Lib\\site-packages\\cv2\\cv2.cp37-win_amd64.pyd'
Consider using the `--user` option or check the permissions.

pip install --user  opencv-contrib-python