centos 6.4版本下已经带python2.6版本，现升级到2.7.11版本。

1、查看版本

#python -V
Python 2.6.6

2、安装前准备，安装相关库
#yum install gcc gcc-c++ autoconf automake
#yum install openssl openssl-devel
3、下载安装
#wget https://www.python.org/ftp/python/2.7.11/Python-2.7.11.tgz
#tar -xvzf Python-2.7.11.tgz
#cd Python-2.7.11
#./configure --prefix=/usr/local/python2.7
#make
#make install
4、修改python链接指向
#mv /usr/bin/python /usr/bin/python2.6.6.old
#ln -s /usr/local/python2.7/bin/python /usr/bin/python
查看版本
# python -V
Python 2.7.11
5、修改yum使用的python版本
虽然现在python已经安装完成，但是使用yum命令会有问题——yum不能正常工作：
# 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:
2.7.11 (default,Aug 17 2016,23:54:43)
[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

这是因为yum默认使用的python版本是2.6.6，到哪是现在的python版本是2.7.11，故会出现上述问题，只需要该一下yum的默认python配置版本就行了：
#vi /usr/bin/yum
将文件头部的#!/usr/bin/python改为

#!/usr/bin/python2.6

6、修改环境变量

$vim ~/.bash_profile

修改为：

PYTHON_HOME=/usr/local/python2.7

PATH=$PATH:$HOME/bin:$PYTHON_HOME/bin

$source .bash_profile