new_contents: #!/usr/bin/env python
  
  #
  import string
  
  #
  while 1:
  
      #
      num_str = raw_input('Enter a number: ')
  
      #
      try:
          #
          num_num = string.atoi(num_str)
  
          #
          break
  
      #
      except ValueError:
          print "invalid input... try again"
  
  #
  fac_list = range(1, num_num+1)
  print "BEFORE:", `fac_list`
  
  #
  i = 0
  
  #
  while i < len(fac_list):
  
      #
      if num_num % fac_list[i] == 0:
          del fac_list[i]
  
      #
      i = i+1
  
  #
  print "AFTER:", `fac_list`
  
subject: Create buggy.py