首页 > 技术文章 > 默克尔树的python简单实现

iamxzc 2019-05-16 11:14 原文

# coding=utf-8
import math
import random
import hashlib
class Node:
def __init__(self,item):
self.item = item
self.child1 = None
self.child2 = None
self.hash = None
self.data = None
def change_data(self,data):
self.data=data
self.hash = hashlib.md5(data.encode('utf-8')).hexdigest()[8:-8] #hexdigest()返回摘要,作为十六进制数据字符串值 [8:-8]将32位MD5转换为16进制
print("make_hash",self.hash,"size",len(self.hash),end=" ")
return self.hash
:
def __init__(self):
self.root = None
class Tree
def add(self, item):#逐层添加子节点
node = Node(item)
end_str = make_data(item)
print("add node ",item)
if end_str !=None and end_str != -1:
node.change_data(end_str)
print("data= %s " % (node.data))
print("hash= %s " % (node.hash))
if self.root is None:
self.root = node
else:
q = [self.root]
while True:
pop_node = q.pop(0)
if pop_node.child1 is None:
pop_node.child1 = node
return
elif pop_node.child2 is None:
pop_node.child2 = node
return
else:
q.append(pop_node.child1)
q.append(pop_node.child2)

def reload_hash(self): # 层次遍历更新hash
if self.root is None:
return None
q = [self.root]
item = [(self.root.item,self.root.data,self.root.hash)]
while q != []:
pop_node = q.pop(0)
if pop_node.child1 and pop_node.child2 :
if pop_node.child1.hash and pop_node.child2.hash:
print("更新基础节点",pop_node.item,end=" ")
end_str=pop_node.child1.hash+pop_node.child2.hash
end_hash=pop_node.change_data(end_str)
print("end_hash= %s " % (end_hash))

if pop_node.child1 is not None:
q.append(pop_node.child1)

if pop_node.child2 is not None:
q.append(pop_node.child2)
return
def traverse(self): # 层次遍历
if self.root is None:
return None
q = [self.root]
item = [(self.root.item,self.root.data,self.root.hash)]
while q != []:
pop_node = q.pop(0)
if pop_node.child1 is not None:
q.append(pop_node.child1)
item.append((pop_node.child1.item,pop_node.child1.data,pop_node.child1.hash))

if pop_node.child2 is not None:
q.append(pop_node.child2)
item.append((pop_node.child2.item,pop_node.child2.data,pop_node.child2.hash))

return (item)

def make_data(i):
if i>6 and i<15:
raw_str = "xizzhongcai15310120233"
nums = math.floor(1e5 * random.random())
nums = str(nums)
nums = nums.zfill(5)
end_str = raw_str + nums
print("end_str",end_str)
return end_str
elif i>=0 and i<7:
return None
else:
return -1

# t = Tree()
# for i in range(15):
# t.add(i)
if __name__ == '__main__':
t = Tree()
for i in range(7): # 基础节点
t.add(i)

for i in range(7, 15): # 带数据的节点
t.add(i)
for i in range(4,0,-1): #刷新基础节点hash值
print("第",i,'层节点hash刷新:')
print(t.reload_hash())

print('前序遍历:\n节点名:数据:hash值',t.traverse())

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