macs.py

import re

macs = 'C4544423F6D7'\
'C4544423F74A'\
'C4544423F6E1'\
'C454441E3602'\
'C454441E3554'\
'C454441E37D3'\
'C454441E37A9'\
'C454441E370A'\
'C454441E379A'\
'C454441E37D0'\
'C454441E361D'\
'C454441E3551'\
'C454441E35C6'\
'C454441E37E5'\
'C454441E3629'\
'C454441E35D5'\
'C454441E3698'\
'C454441E3614'\
'C454441E3692'\
'C454441E364A'\
'C454441E3512'\
'C454441E3623'\
'C454441E369B'\
'C454441E35BD'\
'C454441E359F'

macs = macs.lower()
n = 12
for mac in [macs[i:i+n] for i in range(0, len(macs), n)]:
    print ':'.join(a+b for a,b in zip(mac[::2], mac[1::2]))