【区块链时代】如何用Python实现区块链中的区块结构(快速入手01）-Toy模板网

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区块结构的详细介绍，容易入手：
【区块链时代】如何理解区块链中共识机制以及在区块链中分叉是如何解决的

一、区块链开发环境准备

HTTP协议
Postman / curl 测试工具
Python
Pycharm
Pip工具
Flask/ request

二、区块的结构

{
    "index":0,    #索引
    "timestamp":"",  #时间戳
    "translations": [  #交易信息
        {
            "sender":"",  #交易发送者
            "recipient": "", #交易接收者
            "amount": 5, #交易金额
        }
    ],
    "proof": "", #工作量证明
    "previous_hash":"", #上一个区块hash值
}

三、创建一个区块

import hashlib
import json
from time import time,sleep

class Blockchain:

    def __init__(self):
        self.chain = []
        self.current_translations = []
        # 创建创世区块
        self.new_block(proof = 100 , previous_hash = 1)

    def new_block(self,proof,previous_hash = None):
        block = {
            'index': len(self.chain) + 1,
            'timestamp': time(),
            'translations': self.current_translations,
            'proof': proof,
            'previous_hash': previous_hash or self.hash(self.last_block),
        }
        self.current_translations = []
        self.chain.append(block)
        return block

    # 实现交易
    def new_translation(self,sender,recipient,amount) -> int:
        self.current_translations.append(
            {
                "sender":sender,
                "recipient":recipient,
                "amount":amount
            }
        )
        return self.last_block['index'] + 1

    @staticmethod
    def hash(block):
        block_string = json.dumps(block,sort_keys=True).encode() # 将block(json对象)转换为字符串
        return hashlib.sha256(block_string).hexdigest()

    @property
    def last_block(self):
        return self.chain(-1)

    def proof_of_work(self,last_block:int) -> int:
        proof = 0
        while self.valid_proof(last_block,proof) is False:
            proof += 1
        print("proof is ",proof)
        return proof

    def valid_proof(self, last_proof:int, proof:int) -> bool:
        guess = f'{last_proof}{proof}'.encode()
        guess_hash = hashlib.sha256(guess).hexdigest()
        sleep(1)
        print("guess_hash is ",guess_hash)

        # return guess_hash[0:4] == "0000"
        if guess_hash[0:4] == "0000":
            return True
        else:
            return False

# 测试
testPow = Blockchain()
testPow.proof_of_work(100)

结果如下:

guess_hash is  ccbde76c925125361a6ab2ec97dbb0bb3376bd5f165ca71b8cf9b1851fce1251
guess_hash is  6fe3a4d4ab5e4dbf25ad2e6c5a9e177b3e8e9728fcd60f1bbf75e30592cc7d61
guess_hash is  7b501a4208b6b1a3afe9249a145f73df675eb13a0888b44d6e746f285320fd08
guess_hash is  08936563aaa2e39c721bfb074529904ffae85d2869493405d51442e25b5f1551
guess_hash is  81c5cd1bcca9c78d8d51c76dfb1770bf6509f09c3760179060f12057cf2281ee
guess_hash is  caf42c350b933954e087b008bb5f8457f6cd247f4c06788ecd804a3a8c35cfe1
guess_hash is  c20da575724013406f330c1e2646d7b8cf2bda2abd60c150da1226c9bfda64cc
guess_hash is  7ee9410967a25bb5fa1e216346ae62567594f8c866bfbb1f4c750799cf178cda

四、实现节点通信功能

from flask import Flask
from blockchain import Blockchain

app = Flask(__name__)

@app.route('/index',methods=['GET'])
def index():
    return "Hello BlockChain"

# 添加新的交易
@app.route('/transactions/new',methods=['POST'])
def new_transaction():
    return "我们添加新的交易"

# 挖矿
@app.route('/mine',methods=['GET'])
def mine():
    return "挖矿进行中~~~~~~~~~~~~~~~~~~~"

# 返回完整区块链信息
@app.route('/chain',methods=['GET'])
def full_chain():
    return "返回完整区块链信息"

if __name__ == '__main__':
    app.run(host='0.0.0.0',port=5000)