由于功能及程序依赖，需要将Centos上的python从2.6升级成2.7，把碰到的一些问题记录如下：
安装好2.7后将原来的/usr/bin/python改成/usr/bin/python26，并将2.7的bin目录加入执行路径
Question1： 执行yum报No module named yum
[root@zejin240 ~]# yum list 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: 2.7.12 (default, Jul 6 2016, 18:40:00) [GCC 4.4.7 20120313 (Red Hat 4.4.7-17)] If you cannot solve this problem yourself, please go to the yum faq at: http://yum.baseurl.org/wiki/Faq
解决方法：
vi /usr/binyum
#!/usr/bin/python26
Question2: 执行pip时提示 ImportError: No module named pip
Questions3:源码安装paramiko出现各种模块找不到
解决方法：
pip install -I pycrypto
pip install -I paramiko
Centos6.5 python升级成2.7版本出现的一些问题解决方法
原文：http://www.cnblogs.com/zejin2008/p/5651133.html