python实现二叉树的创建和遍历，python实现二叉树,#coding:utf-

python实现二叉树的创建和遍历，python实现二叉树,#coding:utf-

#coding:utf-8#author:Elvisclass TreeNode(object):    def __init__(self):        self.data = '#'        self.l_child = None        self.r_child = Noneclass Tree(TreeNode):    #create a tree    def create_tree(self, tree):        data = raw_input('->')        if data == '#':            tree = None        else:            tree.data = data            tree.l_child = TreeNode()            self.create_tree(tree.l_child)            tree.r_child = TreeNode()            self.create_tree(tree.r_child)    #visit a tree node    def visit(self, tree):        #输入#号代表空树        if tree.data is not '#':            print str(tree.data) + '\t',    #先序遍历    def pre_order(self, tree):        if tree is not None:            self.visit(tree)            self.pre_order(tree.l_child)            self.pre_order(tree.r_child)    #中序遍历    def in_order(self, tree):        if tree is not None:            self.in_order(tree.l_child)            self.visit(tree)            self.in_order(tree.r_child)    #后序遍历    def post_order(self, tree):        if tree is not None:            self.post_order(tree.l_child)            self.post_order(tree.r_child)            self.visit(tree)t = TreeNode()tree = Tree()tree.create_tree(t)tree.pre_order(t)print '\n'tree.in_order(t)print '\n'tree.post_order(t)