python升级安装后的yum的修复

升级python版本号后，执行yum
# yum -y install openssl
提演示样例如以下:
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:
2.7.3 (default, Jul 15 2014, 16:52:36) 
[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

分析应该是yum和Python是依赖关系，yum是python的模块，所以须要改动yum来解决:
1. 查看python的安装路径
# python
Python 2.7.3 (default, Jul 15 2014, 16:52:36) 
[GCC 4.1.2 20080704 (Red Hat 4.1.2-48)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>
# whereis python
python: /usr/bin/python2.4 /usr/bin/python /usr/bin/python2.6 /usr/lib/python2.4 /usr/local/bin/python 
/usr/local/bin/python2.6-config /usr/local/bin/python3.3-config /usr/local/bin/python3.3 /usr/local/bin/python3.3m 
/usr/local/bin/python3.3m-config /usr/local/bin/python2.6 /usr/local/lib/python2.4 /usr/local/lib/python3.3 
/usr/local/lib/python2.6 /usr/include/python2.4 /usr/share/man/man1/python.1.gz

2. 改动yum
# vim /usr/bin/yum
将 #!/usr/bin/python 改成  #!/usr/bin/python2.4
【保存并退出】

3. 再測试yum安装，成功；