yum命令升级的时候，报出这个错误。

There was a problem importing one of the Python modulesrequired to run yum. The error leading to this problem was:   No module named yumPlease install a package which provides this module, orverify that the module is installed correctly.It's possible that the above module doesn't match thecurrent version of Python, which is:2.7.5 (default, Sep  3 2013, 23:16:48) [GCC 4.6.3 20120306 (Red Hat 4.6.3-2)]

     解决方法：

sudo vim /usr/bin/yum#修个python所在的路径，比如#/usr/local/bin/python2.6