python 模拟区块链 python写区块链

使用python2.7环境实现

import hashlib as hasher
 import datetime as date

#首先定义一个区块类
 class Block:
 # 在实例化的过程中（创造区块），会有本区块的索引，时间戳，区块数据，以及父区块hash
 def init(self,index,timestamp,data,previous_hash):
 self.index = index
 self.timestamp = timestamp
 self.data = data
 self.previous_hash = previous_hash
 self.hash = self.hash_block()def hash_block(self):
 # 采用sha256进行加密
 sha = hasher.sha256()
 sha.update(str(self.index) + str(self.timestamp) + str(self.data) + str(self.previous_hash))
 # 返回十六进制结果，起到双重加密的作用
 return sha.hexdigest()#创建创世区块
 def create_god_block():
 # 手动构造区块链，索引为0，时间戳获取，区块数据，父hash赋值
 return Block(0,date.datetime.now(),‘Genesis Block’,“0”)#实现创世区块后区块创建
 def next_block(last_block):
 this_index = last_block.index + 1
 this_timestamp = date.datetime.now()
 this_data = “hello world” + str(this_index)
 this_fa_hash = last_block.hash
 return Block(this_index,this_timestamp,this_data,this_fa_hash)#使用列表实现区块链的创建
 blockchain = [create_god_block()]
 previous_block = blockchain[0]#定义区块链最终数量，并添加块到链上
 num_totalblock = 20
 for i in range(0,num_totalblock):
 new_block = next_block(previous_block)
 blockchain.append(new_block)
 previous_block = new_block
 print(‘Block #{} has been added to the blockchain’.format(new_block.index))
 print(‘Hash: {}\n’.format(new_block.hash))