Size and Height of a Binary Tree

class BinaryTree:
    def __init__(self, root):
        self.root = root
        self.leftChild = None
        self.rightChild = None
        
    def setRoot(self, root):
        self.root = root
        
    def getRoot(self):
        return self.root
    
    def getLeftChild(self):
        return self.leftChild
    
    def getRightChild(self):
        return self.rightChild
    
    def insertLeftChild(self, newNode):
        if self.leftChild == None:
            self.leftChild = BinaryTree(newNode)
        else:
            t = BinaryTree(newNode)
            t.leftChild = self.leftChild
            self.leftChild = t
            
    def insertRightChild(self, newNode):
        if self.rightChild == None:
            self.rightChild = BinaryTree(newNode)
        else:
            t = BinaryTree(newNode)
            t.rightChild = self.rightChild
            self.rightChild = t


'''recursive process for finding height of a binary tree'''
def height(tree):
    if tree == None:
        return 0
    else:
        return max(height(tree.leftChild),height(tree.rightChild)) + 1

'''iterative process for finding height of a binary tree'''    
def heightIterative(tree):
    height = 0
    if tree == None:
        return 0
    
    queue = []
    queue.append(tree)
    queue.append("NULL")
    
    while ( queue != []):
        root = queue.pop(0)
        if root == "NULL":
            if queue != []:
                queue.append("NULL")
            height += 1
        else:
            if root.getLeftChild():
                queue.append(root.getLeftChild())
            if root.getRightChild():
                queue.append(root.getRightChild())
                
    return height
                
    
'''recursive process for finding size of a binary tree'''    
def size(tree):
    if tree == None:
        return 0
    else:
        return size(tree.getLeftChild()) + 1+ size(tree.getRightChild())

if __name__ == "__main__":        
        
    r = BinaryTree(5)
    r.insertLeftChild(6)
    r.insertRightChild(7)       
    r.leftChild.insertLeftChild(12)
    r.leftChild.insertRightChild(54)
    r.rightChild.insertRightChild(63)

    print "Height of the tree is:", height(r)
    print "\n\n"

    print "size of the tree is:", size(r)
    print "\n\n"

    print "height of the tree is:", heightIterative(r)
    print "\n\n"