Python实现二叉树

# -*- coding:utf-8 -*-

class Node(object):
def __init__(self,index,left=None,right=None,parent=None):
self.index=index
self.left_child=left
self.right_child=right
self.parent=parent

class BinaryTree(object):
def __init__(self):
self.root=None

def insert(self,node):
n=self.root
if n==None:
self.root=node
return
while True:
if node.index<=n.index:
if n.left_child==None:
node.parent=n
n.left_child=node
break
else:
n=n.left_child
if node.index>n.index:
if n.right_child==None:
node.parent=n
n.right_child=node
break
else:
n=n.right_child

def pre_pravel(self,node):
print(node.index)
if node.left_child!=None:
self.pre_pravel(node.left_child)
if node.right_child!=None:
self.pre_pravel(node.right_child)

tree=BinaryTree()
node_dict={}
for i in range(1,10):
node_dict[i]=Node(i)
tree.insert(node_dict[i])
tree.pre_pravel(tree.root)