def inorder(self, treenode):
'中序（in-order，LNR'
if treenode is 0:
return
self.inorder(treenode.left)
print treenode.data
self.inorder(treenode.right)
def postorder(self, treenode):
'后序（post-order，LRN）遍历'
if treenode is 0:
return
self.postorder(treenode.left)
self.postorder(treenode.right)
print treenode.data
node1 = TreeNode(data=1)
node2 = TreeNode(node1, 0, 2)
node3 = TreeNode(data=3)
node4 = TreeNode(data=4)
node5 = TreeNode(node3, node4, 5)
node6 = TreeNode(node2, node5, 6)
node7 = TreeNode(node6, 0, 7)
node8 = TreeNode(data=8)
root = TreeNode(node7, node8, 'root')
bt = BTree(root)
print u'''
#生成的二叉树
# ------------------------
# root
# 7 8
# 6
# 2 5
# 1 3 4
#
# -------------------------
'''
print '前序（pre-order，NLR）遍历 ：n'
bt.preorder(bt.root)
print '中序（in-order，LNR) 遍历 ：n'
bt.inorder(bt.root)
print '后序（post-order，LRN）遍历 ：n'
bt.postorder(bt.root)
二、.二叉树的非递归遍历
下面就用非递归的方式实现一遍。主要用到了 stack 和 queue维护一些数据节点：
# -*- coding: utf - 8 - *-
class TreeNode(object):
def __init__(self, left=0, right=0, data=0):
self.left = left
self.right = right
self.data = data
class BTree(object):
def __init__(self, root=0):
self.root = root
def is_empty(self):
if self.root is 0:
return True
else:
return False
