python 3 解决 ERROR: Could not find a version that satisfies the requirement xxx 的问题

问题：pyhton 3安装module报错ERROR: Could not find a version that satisfies the requirement config.paths

% pip install config.paths
ERROR: Could not find a version that satisfies the requirement config.paths
ERROR: No matching distribution found for config.paths

通过pip安装时常常会出现ERROR: Could not find a version that satisfies the requirement xxx的问题，常用配置镜像源来解决此问题。如下：

pip install 包名 -i http://pypi.douban.com/simple/ --trusted-host pypi.douban.com

如配置镜像源也解决不了，可以尝试配置环境变量解决。