python 区块链代码实现

区块链是一个分布式的、不可篡改的数据库，可以用于记录交易或其他数据的链式结构。下面是一个简单的 Python 区块链代码实现示例：

import hashlib
import json
from time import time

class Blockchain:
    def __init__(self):
        self.chain = []
        self.current_transactions = []
        self.create_block(proof=1, previous_hash='0')

    def create_block(self, proof, previous_hash):
        block = {
            'index': len(self.chain) + 1,
            'timestamp': time(),
            'transactions': self.current_transactions,
            'proof': proof,
            'previous_hash': previous_hash
        }
        self.current_transactions = []
        self.chain.append(block)
        return block

    def new_transaction(self, sender, recipient, amount):
        self.current_transactions.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()
        return hashlib.sha256(block_string).hexdigest()

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

    def proof_of_work(self, last_proof):
        proof = 0
        while self.valid_proof(last_proof, proof) is False:
            proof += 1
        return proof

    @staticmethod
    def valid_proof(last_proof, proof):
        guess = f'{last_proof}{proof}'.encode()
        guess_hash = hashlib.sha256(guess).hexdigest()
        return guess_hash[:4] == "0000"

这是一个简单的区块链实现，包括创建区块、添加交易、工作量证明和验证等功能。你可以使用该代码作为起点，进一步扩展和优化实现。请注意，这只是一个演示示例，不适用于生产环境。