Python中如何学习区块链技术

mark

要学区块链，Python确实是个好起点。直接给你个能跑的区块链核心代码，跑起来就懂了。

import hashlib
import json
from time import time
from typing import List, Dict, Any

class Block:
    def __init__(self, index: int, transactions: List[Dict], timestamp: float, previous_hash: str):
        self.index = index
        self.transactions = transactions
        self.timestamp = timestamp
        self.previous_hash = previous_hash
        self.nonce = 0
        self.hash = self.calculate_hash()
    
    def calculate_hash(self) -> str:
        block_string = json.dumps({
            "index": self.index,
            "transactions": self.transactions,
            "timestamp": self.timestamp,
            "previous_hash": self.previous_hash,
            "nonce": self.nonce
        }, sort_keys=True).encode()
        return hashlib.sha256(block_string).hexdigest()
    
    def mine_block(self, difficulty: int):
        while self.hash[:difficulty] != "0" * difficulty:
            self.nonce += 1
            self.hash = self.calculate_hash()

class Blockchain:
    def __init__(self):
        self.chain: List[Block] = []
        self.difficulty = 4
        self.pending_transactions: List[Dict] = []
        self.create_genesis_block()
    
    def create_genesis_block(self):
        genesis_block = Block(0, [], time(), "0")
        genesis_block.mine_block(self.difficulty)
        self.chain.append(genesis_block)
    
    def get_latest_block(self) -> Block:
        return self.chain[-1]
    
    def add_transaction(self, sender: str, recipient: str, amount: float):
        self.pending_transactions.append({
            "sender": sender,
            "recipient": recipient,
            "amount": amount
        })
    
    def mine_pending_transactions(self, miner_address: str):
        block = Block(
            len(self.chain),
            self.pending_transactions,
            time(),
            self.get_latest_block().hash
        )
        block.mine_block(self.difficulty)
        self.chain.append(block)
        self.pending_transactions = []
    
    def is_chain_valid(self) -> bool:
        for i in range(1, len(self.chain)):
            current_block = self.chain[i]
            previous_block = self.chain[i-1]
            
            if current_block.hash != current_block.calculate_hash():
                return False
            if current_block.previous_hash != previous_block.hash:
                return False
        
        return True

# 使用示例
if __name__ == "__main__":
    my_blockchain = Blockchain()
    
    # 添加交易
    my_blockchain.add_transaction("Alice", "Bob", 10)
    my_blockchain.add_transaction("Bob", "Charlie", 5)
    
    # 挖矿
    print("开始挖矿...")
    my_blockchain.mine_pending_transactions("miner_address")
    print(f"区块 #{my_blockchain.get_latest_block().index} 已挖出")
    print(f"哈希: {my_blockchain.get_latest_block().hash}")
    
    # 验证链
    print(f"区块链有效: {my_blockchain.is_chain_valid()}")
    
    # 查看链信息
    print(f"\n区块链长度: {len(my_blockchain.chain)}")
    for block in my_blockchain.chain:
        print(f"区块 #{block.index}: {block.hash}")

这个代码实现了区块链的核心：区块结构、哈希计算、工作量证明（挖矿）、交易处理和链验证。跑起来看看每个区块怎么生成的，哈希怎么算的，链怎么连起来的。

学区块链别光看理论，先把这个代码跑通，然后自己改改：试试改难度值看挖矿时间变化，加个交易验证逻辑，或者实现个简单的P2P网络。理解了这些基础概念，再去看智能合约（用web3.py）、以太坊这些就顺了。

一句话建议：从实现基础区块链开始，边写代码边理解核心概念。