old_contents: #! /usr/bin/python
  
  from operator import add, sub
  from random import randint, choice
  
  ops = {'+': add, '-': sub}
  MAXTRIES = 2
  
  def doprob():
      op = choice('+-')
      nums = [randint(1, 10) for i in range(2)]
      nums.sort(reverse=True)
      ans = ops[op](*nums)
      pr = '%d %s %d = ' % (nums[0], op, nums[1])
      oops = 0
  
      while True:
          try:
              if int(raw_input(pr)) == ans:
                  print 'correct'
                  break
              if oops == MAXTRIES:
                  print 'answer\n%s%d' % (pr, ans)
              else:
                  print 'incorrect... try again'
                  oops += 1
          except (KeyboardInterrupt, EOFError, ValueError):
              print 'invalid input... try again'
  
  def main():
      while True:
          doprob()
          try:
              opt = raw_input('Again? [y]').lower()
              if opt and opt[0] == 'n':
                  break
          except(KeyboardInterrupt, EOFError):
              break
  
  if __name__ == '__main__':
      main()
new_contents: #! /usr/bin/python
  
  
  from operator import add, sub
  from random import randint, choice
  
  ops = {'+': add, '-': sub}
  MAXTRIES = 2
  
  def doprob():
      op = choice('+-')
      nums = [randint(1, 10) for i in range(2)]
      nums.sort(reverse=True)
      ans = ops[op](*nums)
      pr = '%d %s %d = ' % (nums[0], op, nums[1])
      oops = 0
  
      while True:
          try:
              if int(raw_input(pr)) == ans:
                  print 'correct'
                  break
              if oops == MAXTRIES:
                  print 'answer\n%s%d' % (pr, ans)
              else:
                  print 'incorrect... try again'
                  oops += 1
          except (KeyboardInterrupt, EOFError, ValueError):
              print 'invalid input... try again'
  
  def main():
      while True:
          doprob()
          try:
              opt = raw_input('Again? [y]').lower()
              if opt and opt[0] == 'n':
                  break
          except(KeyboardInterrupt, EOFError):
              break
  
  if __name__ == '__main__':
      main()
subject: create new files.