Get system load using Python Script

I have written a simple python script that collect system load information and store in a XML file.

#!/usr/bin/env python

import os
import commands
import time
from time import gmtime, strftime

while 0 < 10:
 
 file_name = strftime("%Y_%m_%d_%H_%M", gmtime()) 

 data =  commands.getoutput("w | grep load")
 xml_data = ""+ data + ""
 
 print xml_data
 
 
 if os.path.isfile(file_name + ".xml"):
  x=0
 else:

  f_prev=open(file_name + ".xml", 'a')
  f_prev.write("")
  f_prev.close

  f=open(file_name + ".xml", 'w')
  f.write("\n\n")
  f.close()

 
 f=open(file_name + ".xml", 'a')

 f.write(xml_data+"\n")

 f.close()
 time.sleep(3)

We will get XML file like this.

<?xml version='1.0' encoding='utf-8'?>
<data>
<load> 01:40:38 up 6:27, 3 users, load average: 0.07, 0.07, 0.03</load>
<load> 01:40:48 up 6:27, 3 users, load average: 0.06, 0.07, 0.03</load>
<load> 01:40:58 up 6:27, 3 users, load average: 0.05, 0.07, 0.03</load>
</data>