遇到问题---centos---运行yum报错：No module named yum

情况

我们在公司的集群环境想要使用yum命令进行安装一些组件，报错No module named yum。

完整报错信息如下:

There was a problem importing one of the Python modules
required to run yum. The error leading to this problem was:

   No module named yum

Please install a package which provides this module, or
verify that the module is installed correctly.

It's possible that the above module doesn't match the
current version of Python, which is:
2.7.