gistfile1.txt

class Tree(object):
   def __init__(self, cargo, left=None, right=None):
      self.cargo = cargo
      self.left = left
      self.right = right

   def __str__(self):
      return str(self.cargo)

   #Traversing threw the tree
   def total(tree):
      if tree == None: return 0
      return total(tree.left) + total(tree.right) + tree.cargo

#Allocating the child nodes
#left = Tree(2)
#right = Tree(3)
tree = Tree(1, Tree(2), Tree(3))
print total(tree)