No module named yum 错误

在centos上，yum工具是一个很好用、很强大的工具，在系统一些软件升级之后，特别是python升级之后，发现yum 不好用了。

出现这样的错误提示

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:2.7.2 (default, Nov  8 2012, 23:03:00) [GCC 4.1.2 20080704 (Red Hat 4.1.2-48)]If you cannot solve this problem yourself, please go to the yum faq at:  http://wiki.linux.duke.edu/YumFaq

错误提示python版本不匹配，修改yum工具默认的python版本。

vi /usr/bin/yum

打开脚本文件

#!/usr/bin/pythonimport systry:    import yum。。。。。。。

修改为

#!/usr/bin/python2.4import systry:    import yumexcept ImportError:

因为重新升级或者安装了python，所以重新指定版本。

测试OK。