为什么80%的码农都做不了架构师？>>> 
Python升级导致yum不可用 “ No module named yum”
[root@localhost python]# yum
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:
2.7.13 (r266:84292, Jan 22 2014, 09:37:14)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-4)]
If you cannot solve this problem yourself, please go to
the yum faq at:
http://yum.baseurl.org/wiki/Faq解决办法：python和yum 全部卸载 重新安装
步骤1：卸载python
rpm -qa|grep python|xargs rpm -e --allmatches --nodeps whereis python|xargs rm -fr
步骤2：卸载yum
rpm -qa|grep yum|xargs rpm -e --allmatches --nodeps rm -rf /etc/yum.repos.d/* whereis yum|xargs rm -fr
步骤3：安装python 和 yum
从linux安装包ISO文件中，查找到python和yum相关的rpm文件，上传到linux服务器
mkdir /usr/local/src/python
// 上传*python*.rpm 文件到此路径下
rpm -ivh --nodeps *python* mkdir /usr/local/src/yum
// 上传*yum*.rpm 文件到此路径下
rpm -ivh --nodeps *yum*步骤4：测试
[root@localhost yum]# python
Python 2.6.6 (r266:84292, Feb 22 2013, 00:00:18)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-3)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>
[root@localhost yum]# yum --version
3.2.29
Installed: rpm-4.8.0-32.el6.x86_64 at 2018-01-30 09:44
Built : CentOS BuildSystem <http://bugs.centos.org> at 2013-02-22 02:13
Committed: Florian Festi <ffesti@redhat.com> at 2012-11-15
Installed: yum-3.2.29-40.el6.centos.noarch at 2018-02-02 06:27
Built : CentOS BuildSystem <http://bugs.centos.org> at 2013-02-22 11:26
Committed: Johnny Hughes <johnny@centos.org> at 2013-02-21
Installed: yum-plugin-aliases-1.1.30-14.el6.noarch at 2018-02-02 06:27
Built : CentOS BuildSystem <http://bugs.centos.org> at 2012-06-22 12:23
Committed: Zdenek Pavlas <zpavlas@redhat.com> at 2012-04-26
Installed: yum-plugin-fastestmirror-1.1.30-14.el6.noarch at 2018-02-02 06:27
Built : CentOS BuildSystem <http://bugs.centos.org> at 2012-06-22 12:23
Committed: Zdenek Pavlas <zpavlas@redhat.com> at 2012-04-26