title: python has multiple versions for different users
body: <p>I was running my python script by <code>sudo</code>, it throws an exception, then I found the python versions are different as follows, I'm using CentOS 6:</p>
  
  <pre><code>[haifzhan@home]$ sudo python --version
  Python 2.6.6
  [haifzhan@home]$ sudo su -
  [root@home ~]# python --version
  Python 2.7.5
  [haifzhan@home]$ python --version
  Python 2.7.5
  </code></pre>
  
  <p>When I login as root or my username, the python version is 2.7, but when I use <code>sudo</code> to run, it is 2.6.</p>
  
  <p>Can anyone tell me how to make them all to version 2.7, what should I configure?</p>