python: Installation of python2.7 under Centos6

1) Compile and install python2.7

[root@mysql-master ~]# python -V
Python 2.6.6
查看python的版本信息（之前的yum是通过yum安装的）
[root@mysql-master src]# wget https://www.python.org/ftp/python/2.7.9/Python-2.7.9.tar.xz
[root@mysql-master src]# file Python-2.7.9.tar.xz 
Python-2.7.9.tar.xz: xz compressed data
[root@mysql-master src]# xz -d Python-2.7.9.tar.xz 
[root@mysql-master src]# ls
debug  kernels  Python-2.7.9.tar
[root@mysql-master src]# tar -xf Python-2.7.9.tar 
[root@mysql-master src]# cd Python-2.7.9
[root@mysql-master Python-2.7.9]# ./configure 
[root@mysql-master Python-2.7.9]# make && make install
[root@mysql-master Python-2.7.9]# echo $?
0
[root@mysql-master Python-2.7.9]# /usr/local/bin/python2.7 -V
Python 2.7.9
[root@mysql-master Python-2.7.9]# mv /usr/bin/python /usr/bin/python2.6
mv：是否覆盖"/usr/bin/python2.6"？ yes
[root@mysql-master Python-2.7.9]# ln -s /usr/local/bin/python2.7 /usr/bin/python
[root@mysql-master Python-2.7.9]# python -V
Python 2.7.9

2) Adjust the yum configuration

因为yum使用会调用python的信息，避免重新安装python后，yum出现报错，编辑yum的文件：
[root@mysql-master Python-2.7.9]# sed -i 's@#!/usr/bin/python@#!/usr/bin/python2.6@g' /usr/bin/yum
[root@mysql-master Python-2.7.9]# cat /usr/bin/yum |head
#!/usr/bin/python2.6
import sys
try:
    import yum
except ImportError:
    print >> sys.stderr, """\
There was a problem importing one of the Python modules
required to run yum. The error leading to this problem was:
   %s
[root@mysql-master Python-2.7.9]# python
Python 2.7.9 (default, Nov 16 2016, 19:53:47) 
[GCC 4.4.7 20120313 (Red Hat 4.4.7-16)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> print "hello,world"
hello,world
到此，python2.7的基本安装也完成了。