nautilus script : backup script

This script copy the selected files in the folder named 'old'.
If the folder is not exist, the script create 'old' folder.
Time stamp strings, e.g. "_Thu_Jul_30_11.05.39_2009", are automatically attached at the end of the file name.

#!/usr/bin/python
# -*- coding: UTF-8 -*-

import os, glob, time

old = 'old'        # backup folder name

def showme(s):
   os.system('gmessage -center ' + str(s))
 
def make_time_str():
   tmp = time.ctime()
   tmp = tmp.replace(' ', '_')
   tmp = tmp.replace(':', '.')
   return tmp
 
def make_old_folder():
   if len(glob.glob(old)) == 1 and os.path.isdir(old) :
       pass #
   else :
       os.system('mkdir old')
     
   return
 
make_old_folder()

# get selected file paths
tmp = os.environ['NAUTILUS_SCRIPT_SELECTED_FILE_PATHS']
fns = tmp.strip().split('\n')     #filenames

for fn in fns :        # for filename in filenames
   if os.path.isdir(fn) :
       #showme('pass')
       pass
   fn_nameonly = os.path.basename(fn)    # extract file name from file path
   #showme(os.path.splitext(fn)[1])
   cmd = 'cp ' + '"' + fn_nameonly + '" old/"' + fn_nameonly + '_' + make_time_str() + os.path.splitext(fn)[1] + '"'
   os.system(cmd)

The script file must be in ~/.gnome2/nautilus-scripts/