到底什么是区块链

import hashlib
import time

class Block:
    def __init__(self, index, data, previous_hash):
        self.index = index
        self.data = data
        self.timestamp = time.time()
        self.previous_hash = previous_hash
        self.hash = self.calculate_hash()

    def calculate_hash(self):
        value = str(self.index) + str(self.data) + str(self.timestamp) + str(self.previous_hash)
        return hashlib.sha256(value.encode('utf-8')).hexdigest()

class Blockchain:
    def __init__(self):
        self.chain = [self.create_genesis_block()]

    def create_genesis_block(self):
        return Block(0, "Genesis Block", "0")

    def add_block(self, data):
        previous_block = self.chain[-1]
        new_block = Block(previous_block.index + 1, data, previous_block.hash)
        self.chain.append(new_block)

# 示例使用
blockchain = Blockchain()
blockchain.add_block("Transaction 1")
blockchain.add_block("Transaction 2")
for block in blockchain.chain:
    print(f"Index: {block.index}, Data: {block.data}, Hash: {block.hash}")