1 class C: 2 def __init__(self, x): 3 self.x = x 4 5 def value(self): 6 return self.x 7 8 def length(self): 9 return self.double(self.value()) 10 11 def double(self, x): 12 return x * 2 13 14 c = C(3) 15 print c.length() # 6 16 17 # Explicit function for addition purposes. 18 19 def combine(x, y, z): 20 return x + y + z 21 22 class Tree: 23 def __init__(self, item, left=None, right=None): 24 self.item = item 25 self.left = left 26 self.right = right 27 28 def count(self): 29 if self.left and self.right: 30 # Test calls in parameter lists needing separate temporary storage. 31 return combine(self.item, self.left.count(), self.right.count()) 32 else: 33 return self.item 34 35 tree = \ 36 Tree(10000, 37 Tree(2000, 38 Tree(300), 39 Tree(40) 40 ), 41 Tree(5)) 42 43 print tree.count() # 12345
