CentOS 6.8自带的是Python 2.6.6，yum中最新的也是Python 2.6.6，只能下载Python 2.7.12的源代码自己编译安装。
操作步骤如下：
1）安装Development tools
yum groupinstall "Development tools"
2）安装编译Python需要的包包
yum install zlib-devel
yum install bzip2-devel
yum install openssl-devel
yum install ncurses-devel
yum install sqlite-devel
yum install tcl-devel
yum install tk-devel
3）
下载并解压Python 2.7.12的源代码
cd /opt
wget --no-check-certificate https://www.python.org/ftp/python/2.7.12/Python-2.7.12.tar.xz
tar xf Python-2.7.12.tar.xz
cd Python-2.7.12
4）编译与安装Python 2.7.12
./configure --prefix=/usr/local
make && make install
5）将python命令指向Python 2.7.12（可省略）
ln -s /usr/local/bin/python2.7 /usr/local/bin/python
6）检查Python版本
# python --version
Python 2.7.12
