#用类定义二叉树

class BTree:

def

__init__(self,value):

#左儿子

self.left =

None

#节点值

self.data =

value

#右儿子

self.right

= None

#向左子树插入节点

def

insertLeft(self,value):

self.left =

BTree(value)

return

self.left

#向右子树插入节点

def insertRight(self,value):

self.right

= BTree(value)

return

self.right

#输出节点数据

def show(self):

print

self.data

#判断是否为叶子

def isLeaf(self):

return ((not self.left) and

(not self.right))

#得到右孩子

def getRightChild(self):

return self.right

#得到左孩子

def getLeftChild(self):

return self.left

#先序遍历

def preorder(self,node):

if node.data:

node.show()

if

node.left:

self.preorder(node.left)

if

node.right:

self.preorder(node.right)

#中序遍历

def inorder(self,node):

if node.data:

if

node.left:

self.inorder(node.left)

node.show()

if

node.right:

self.inorder(node.right)

#后序遍历

def postorder(self,node):

if node.data:

if

node.left:

self.postorder(node.left)

if

node.right:

self.postorder(node.right)

node.show()

#树高

def height(tree):

if tree ==

None:

return -1

else:

return 1 +

max(height(tree.left),height(tree.right))

if __name__ == '__main__':

Root = BTree('D')

B = Root.insertLeft('B')

E = Root.insertRight('E')

A = B.insertLeft('A')

C = B.insertRight('C')

G = E.insertRight('G')

F = G.insertLeft('F')

print

'***********************'

print 'Binary tree

pre-travels'

print

'***********************'

Root.preorder(Root)

print

'***********************'

print 'Binary tree

in-travels'

print

'***********************'

Root.inorder(Root)

print

'***********************'

print 'Binary tree

post-travels'

print

'***********************'

Root.postorder(Root)

print A.isLeaf()

B.getLeftChild().show()

B.getRightChild().show()

print height(Root)