误卸载python导致yum无法使用事件(总结)
由于服务器需要升级python，参照了一篇坑爹的文章卸载了旧版python
# 卸载旧的python
sudo rpm -evf --nodeps python
导致yum无法使用
# yum -v
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:
2.7.3 (#1, Feb 3 2012, 15:37:12)
[GCC 4.4.6 20110731 (Red Hat 4.4.6-3)]
If you cannot solve this problem yourself, please go to
the yum faq at:http://wiki.linux.duke.edu/YumFaq
由于yum是基于python
centos6.2默认使用python2.6.6，我又源码安装了一遍python2.6.6，
修改了vi /usr/bin/yum
#/usr/bin/python修改为#/usr/bin/python2.6
执行yum-v还是不行~~
于是就从centos6.2光盘找python和yum的rpm包安装，一番尝试之后，发现有N个package需要重新安装，这里就不写尝试过程，终于搞定！
解决方法如下
cnetos6.2*64光盘rpm包地址http://mirrors.ustc.edu.cn/centos/6.2/os/x86_64/Packages/
需要安装这几个包
python-2.6.6-29.el6.x86_64.rpm
python-devel-2.6.6-29.el6.x86_64.rpm
python-iniparse-0.3.1-2.1.el6.noarch.rpm
python-setuptools-0.6.10-3.el6.noarch.rpm
python-urlgrabber-3.9.1-8.el6.noarch.rpm
rpm-python-4.8.0-19.el6.x86_64.rpm
yum-3.2.29-22.el6.centos.noarch.rpm
yum-metadata-parser-1.1.2-16.el6.x86_64.rpm
python-pycurl-7.19.0-8.el6.x86_64.rpm
注意rpm命令，必须要追加 –replacepkgs 参数，强制其重新安装，否则rpm会报告说package已安装。
rpm -Uvh --replacepkgs ***.rpm
如果仍然无法运行Yum，则运行 Python，import yum，查询下缺少什么东西。
# python
Python 2.6.6 (r266:84292, Dec 7 2011, 20:48:22)
[GCC 4.4.6 20110731 (Red Hat 4.4.6-3)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>import yum
//会提示相关的错误，查找对应的rpm，装上即可，重复此过程，直到 yum 正常
关于yum异常问题处理之“土”方法：
#vim /usr/bin/yum
将首行显示的 !#/usr/bin/python 修改为 !#/usr/bin/python2.6（我的系统默认安装的是python2.6，你也可以用whereis python 查看升级前和升级后的版本）
#############################
源码包安装了 python2.7 想还原为系统默认
whereis python
找到2.7 的python全部删掉，然后执行，yum 如果正常，则看python是否正常
结果有问题：
python
/usr/local/bin/python No such file or directory"
做个软连接就ok
pwd /usr/local
ln -s /usr/local/bin/python2.6 python
本文转自crazy_charles 51CTO博客，原文链接：http://blog.51cto.com/douya/1425492，如需转载请自行联系原作者
