深度遍歷分為先序遍歷，中序遍歷，以及後序遍歷；而深度遍歷的方式又分為遞迴深度遍歷和棧深度遍歷。
廣度優先遍歷是層序遍歷：

#!/usr/bin/env python
#coding:utf-8

class TreeNode(object):
    def __init__(self):
        self.data = '#'
        self.lchild = None
        self.rchild = None

class Tree(TreeNode):
    def __init__(self):
        self.root = TreeNode()
        self.myQueue = []

    #Create a tree
 

    def create_tree(self,tree):
        data = raw_input('->')
        if data == '#':
            tree = None
        else:
            tree.data = data
            tree.lchild = TreeNode()
            self.create_tree(tree.lchild)
            tree.rchild = TreeNode()
            self.create_tree(tree.rchild)

    def
 
 visit(self,tree):
        #輸入#代表空樹
        if tree.data is not '#':
            print str(tree.data)+'\t'

    def pre_order(self,tree):
        if tree is not None:
            self.visit(tree)
            self.pre_order(tree.lchild)
            self.pre_order(tree.rchild)

    def in_order(self,tree)
 
:
        if tree is not None:
            self.in_order(tree.lchild)
            self.visit(tree)
            self.in_order(tree.rchild)

    def post_order(self,tree):
        if tree is not None:
            self.post_order(tree.lchild)
            self.post_order(tree.rchild)
            self.visit(tree)

    def pre_stack(self,tree):
        if tree == None:
            return
        myStack = []
        none = tree
        while node or myStack:
            while node:
                print node.data
                myStack.append(node)
                node = node.lchild
            node = myStack.pop()
            node = node.rchild

    def in_stack(self,tree):
        if tree == None:
            return
        myStack = []
        node = tree
        while node or myStack:
            myStack.append(node)
            node=node.lchild
        node=myStack.pop()
        print node.data
        node=node.rchild

    def post_stack(self,tree):
        if tree == None:
            return
        myStack1 = []
        myStack2 = []
        node=tree
        myStack1.append(node)
        while myStack1:
            node = myStack1.pop()
            if node.lchild:
                myStack1.append(node.lchild)
            if node.rchild:
                myStack1.append(node.rchild)
            myStack2.append(node)
        while myStack2:
            print myStack2.pop().data

    def level_order(self,tree):
        if tree == None:
            return
        myQueue = []
        node = tree
        myQueue.append(node)
        while myQueue:
            node=myQueue.pop(0)
            print node.data
            if node.lchild:
                myQueue.append(node.lchild)
            if node.rchild:
                myQueue.append(node.rchild)