"""File:      read_int.py
   Purpose:   Illustrate exception handling.
   
   Run:       python read_int.py

   Input:     A sequence of lines of characters.  The last should
              consist of a single int.
   Output:    Prompts and error messages, until an int is entered.
              Then the int is printed.
"""
              
def read_int(prompt):
   """Print prompt and read in an int.  Print error message
      if input is incorrect and try again."""

   done = False
   while not done:
      try:
         x = int(raw_input(prompt + "\n   "))
         done = True
      except:
         print "Sorry.  Please try again"
         print
   return x

if __name__ == "__main__":
   x = read_int("Enter an int")
   print "We read", x