You are using pip version 9.0.1, however version 19.0.2 is available. You should consider upgrading

在windows下使用pip安装时出现提示:You are using pip version 9.0.1, however version 19.0.2 is available.
You should consider upgrading via the ‘python -m pip install --upgrade pip’ command.
You are using pip version 9.0.1, however version 19.0.2 is available. You should consider upgrading
You are using pip version 9.0.1, however version 19.0.2 is available. You should consider upgrading
说明pip版本太低,这时需要使用python -m pip install --upgrade pip命令来更新安装包.
但是在命令执行retry几次之后,又会发现更新失败,具体原因是镜像源的问题,我又重新尝试命令:You are using pip version 9.0.1, however version 19.0.2 is available. You should consider upgrading
将镜像源改为国内的,此处使用豆瓣,问题解决了.
再尝试使用pip安装几个包,还是在命令后加上国内镜像源地址:You are using pip version 9.0.1, however version 19.0.2 is available. You should consider upgrading
OK,perfect!!!