You are using pip version 19.0.2, however version 20.2b1 is available.
You should consider upgrading via the 'python -m pip install --upgrade pip' command.提示版本要升级，但是执行python -m pip install --upgrade pip
安装失败，可以尝试先删除在安装的方式
python -m pip uninstall pip删除完成后再执行：
python -m pip install pip
