text: #!/usr/bin/env python
  import os
  import os.path
  import shutil
  import sys
  
  source = sys.argv[1]
  destination = sys.argv[2]
  
  while not os.path.exists(source):
      source = raw_input('Enter a valid source directory\n')
  while not os.path.exists(destination):
      destination = raw_input('Enter a valid destination directory\n')
  
  for root, dirs, files in os.walk(source, topdown=False):
      for file in files:
          extension = os.path.splitext(file)[1][1:].upper()
      destinationPath = os.path.join(destination,extension)
      
      if not os.path.exists(destinationPath):
              os.mkdir(destinationPath)
      if os.path.exists(os.path.join(destinationPath,file)):
              print 'WARNING: this file was not copied :' + os.path.join(root,file)
      else:
          shutil.copy2(os.path.join(root,file), destinationPath)
  