python 写二叉树遍历

在http://www.python.org/下载了编译器，很方便、好用

#树节点类----------------------------------------
class TreeNode(object):
    #初始化构造函数
    def __init__(self,data,left,right):
        self.data=data
        self.left=left
        self.right=right
        pass

    pass

#树----------------------------------------------
class Tree(object):
  
    #获取树
    def get(self):
        n9=TreeNode('n9','','')
        n8=TreeNode('n8','','')
        n7=TreeNode('n7','','')
        n6=TreeNode('n6',n8,n9)
        n5=TreeNode('n5','','')
        n4=TreeNode('n4','','')
        n3=TreeNode('n3',n6,n7)
        n2=TreeNode('n2',n4,n5)
        n1=TreeNode('n1',n2,n3)
        return n1
        pass

 
    #前序遍历
    def preOrder(self,ref):
        if ref=='':
            return
        print ref.data
        self.preOrder(ref.left)
        self.preOrder(ref.right)
        
        pass

    #中序遍历
    def inOrder(self,ref):
        if ref=='':
            return
        self.inOrder(ref.left)
        print ref.data
        self.inOrder(ref.right)
        pass
    
    #后序遍历
    def postOrder(self,ref):
        if ref=='':
            return
        self.postOrder(ref.left)
        self.postOrder(ref.right)
        print ref.data
        pass
   
    pass
#----------------------------------------------------------
#实例化树
tree=Tree()
#获取一棵建好的树
t1=tree.get()

#前序遍历
print '前序遍历'
tree.preOrder(t1)

#中序遍历
print '中序遍历'
tree.inOrder(t1)

#后序遍历
print '后序遍历'
tree.postOrder(t1)