python实现分布式区块链

python实现分布式区块链

import hashlib
import json
from time import time
from urllib.parse import urlparse
from uuid import uuid4
import requests
from flask import Flask, jsonify, request
import math

class Blockchain(object):
    def __init__(self):
        self.current_transactions = []
        self.chain = []
        self.nodes = set()
        # 创建“创世块”
        self.new_block(previous_hash=1, proof=100)

    def register_node(self, address):
        """
        增加一个新的网络节点到set集合
       
        """
        parsed_url = urlparse(address)
        self.nodes.add(parsed_url.netloc)

    def valid_chain(self, chain):
        """
         检查给定的链是否是有效的
        :param chain: <list> 区块链
        :return: <bool> 
        """
        last_block = chain[0]
        current_index = 1
        while current_index < len(chain):
            block = chain[current_index]
            print(f'{last_block}')
            print(f'{block}')
            # 检验当前block的previous_hash值和前面block的hash值是否相等
            if block['previous_hash'] != self.hash(last_block):
                return False
            # 验证前面block的工作量证明和当前block的工作量证明拼接起来的字符串的hash是否以'abc'为开头
            if not self.valid_proof(last_block['proof'], block['proof']):
                return False
            last_block = block
            current_index += 1
        # 验证通过，返回True
        return True

    def resolve_conflicts(self):
        """
        共识算法解决冲突
        使用网络中最长的链.
        :return: <bool> True 如果链被取代, 否则为False
        """
        # 所有的邻居节点
        neighbours = self.nodes
        new_chain = None
        # 在所有邻居中查找比自己链更长的
        max_length = len(self.chain)
        # 遍历并且验证