title: list index out of range
body: <pre><code>#!/usr/bin/python
  
  import os,sys
  from os import path
  
  input = open('/home/XXXXXX/ERR001268_1', 'r').read().split('\n')
  
  at = 1
  for lines in range(0, len(input)):
      line1 = input[lines]
      line4 = input[lines+3]
      num1 = line1.split(':')[4].split()[0]
      num4 = line4.split(':')[4].split()[0]
      print num1,num4
  
  
      at += 1
  </code></pre>
  
  <p>However I got the error: list index out of range</p>
  
  <p>What's the problem here?</p>
  
  <p>btw, besides <code>"at +=1"</code>, is there any other way to finish this cycle loop?
  thx</p>