问题描述：
pip安装库文件时报错：You are using pip version 18.1, however version 21.0.1 is available.
You should consider upgrading via the 'python -m pip install --upgrade pip' command.
执行：
python -m pip install --upgrade pip
报错：
Could not install packages due to an EnvironmentError: [WinError 5] 拒绝访问。: 'C:Program Files (x86)Python37-32Libsite-packagespipinit.py'
Consider using the --user option or check the permissions.
解决方法：
python -m pip install --upgrade pip -i https://pypi.douban.com/simple --user
加上 --user 给予权限搞定。这里用了豆瓣的源。别说还挺快。
完美解决！Successfully！