出現ModuleNotFoundError: No module named ‘cv2‘ 和 WARNING: You are using pip version 20.1.1的解決辦法（如下）

C:\Users\Z>pip install opencv-contrib-python

Collecting opencv-contrib-python

  Downloading opencv_contrib_python-4.5.1.48-cp37-cp37m-win32.whl (31.4 MB)

     |████████████████████████████████| 31.4 MB 108 kB/s

Collecting numpy>=1.14.5

  Downloading numpy-1.20.2-cp37-cp37m-win32.whl (11.3 MB)

     |████████████████████████████████| 11.3 MB 6.4 MB/s

Installing collected packages: numpy, opencv-contrib-python

Successfully installed numpy-1.20.2 opencv-contrib-python-4.5.1.48

WARNING: You are using pip version 20.1.1; however, version 21.0.1 is available.

You should consider upgrading via the 'd:\python\python.exe -m pip install --upgrade pip' command.

C:\Users\Z>python -m pip install --upgrade pip -i https://pypi.douban.com/simple

Looking in indexes: https://pypi.douban.com/simple

Collecting pip

  Downloading https://pypi.doubanio.com/packages/fe/ef/60d7ba03b5c442309ef42e7d69959f73aacccd0d86008362a681c4698e83/pip-21.0.1-py3-none-any.whl (1.5 MB)

     |████████████████████████████████| 1.5 MB 819 kB/s

Installing collected packages: pip

  Attempting uninstall: pip

    Found existing installation: pip 20.1.1

    Uninstalling pip-20.1.1:

      Successfully uninstalled pip-20.1.1

Successfully installed pip-21.0.1