old_contents: """prgm"""
  def add(att1, att2):
      """prgm"""
      sum = int(att1) + int(att2)
      if sum==0:
          return sum 
      elif att1.isdigit and att2.isdigit:
          return sum
          
      else:
          return False
  
  # take input from the user
  print "Addition of two numbers"
  
  #A = raw_input("Enter first number: ")
  #B = raw_input("Enter second number: ")
  A = '45'
  B = '56'
  print A, "+", B, "=", add(A, B)
  
new_contents: """prgm"""
  def add(att1, att2):
      """prgm"""
      sum = int(att1) + int(att2)
      if sum == 0:
          return sum 
      elif att1.isdigit and att2.isdigit:
          return sum
      else:
          return False
  
  # take input from the user
  print "Addition of two numbers"
  
  #A = raw_input("Enter first number: ")
  #B = raw_input("Enter second number: ")
  A = '45'
  B = '56'
  print A, "+", B, "=", add(A, B)
  
subject: Create addition.py