MAC ID Using RE

#!/bin/bash
#Author :Rajeev S
#Date   :8/18/2011 2341hrs
#print mac id of a computer
import re
import os
os.system("clear")
ifconfigOutput=os.popen("ifconfig").read()
t='[a-z0-9]'
MACpattern=(t*2+':')*5+t*2
m=re.search(MACpattern,ifconfigOutput)
print 'MAC address is ',m .group()