[Python Study Notes]一个简单的区块链结构(python 2.7)

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>>文件: csv文件操作.py
>>作者: liu yang
>>邮箱: liuyang0001@outlook.com
>>博客: www.cnblogs.com/liu66blog

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# !/usr/bin/env python2.7
import hashlib as hasher
import datetime as date

class Block:
    def __init__(self, index, data, time, previous_hash):
        self.index = index
        self.data = data
        self.time = time
        self.previous_hash = self.hash_block()

    def hash_block(self):
        sha = hasher.sha256()
        sha.update(str(self.index) + str(date) + str(self.time) + str(self.previous_hash))
        return sha.hexdigest()

'''区块链的起源块'''
def create_genesis_block():
    # 初始化一个区块
    return Block(index=0, time=date.datetime.now(), data='genesis block', previous_hash='0')

'''定义下一个区块'''
def next_block(last_block):
    this_index = last_block+1
    this_time = date.datetime.now()
    this_data = '数据'+str(this_index)
    this_previous_hash = last_block.hash
    return Block(index=this_index, time=this_time, data=this_data, previous_hash=this_previous_hash)

if __name__ == '__main__':

    block_chain = [create_genesis_block()]
    previous_block = block_chain[0]
    num_of_block = 20
    # 添加区块到我们的链上
    for i in range(0,num_of_block):
        block_to_add=next_block(previous_block)
        blockchain.append(block_to_add)
        previous_block=block_to_add
        print('Block #{} has been added to the chain'.format(block_to_add.index))