String to reverse double word

gistfile1.txt

#!/usr/bin/env python
#-*- coding: UTF-8 -*-
# File: stringToReverseDoubleWord.py
# Copyright (c) 2011 by Costas Tyfoxylos
#
# GNU General Public Licence (GPL)
# 
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
# details.
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc., 59 Temple
# Place, Suite 330, Boston, MA  02111-1307  USA
#

import sys

__author__ = 'Costas Tyfoxylos <costas.tyf@gmail.com>'
__docformat__ = 'plaintext'
__date__ = '19/05/2011'


def to_hex(string):
    characters = []
    for character in string:
        byte = hex(ord(character)).replace('0x', '')
        if len(byte) == 1:
            byte = '0'+byte
        characters.append(byte)
    characters.reverse()
    counter = 0
    double_word = ''
    for byte in characters:
        double_word += str(byte)
        counter += 1
        if counter == 4:
            print '0x' + double_word
            double_word = ''
            counter = 0
    if double_word:
        double_word = double_word.zfill(8)
        print '0x' + double_word
    return True

if __name__ == '__main__':
        text = sys.argv[1]
        to_hex(text)