《区块链公链数据分析简易速速上手小册》第3章：区块链数据结构（2024 最新版）（上）

import hashlib
import json
from time import time
class Blockchain:
    def __init__(self):
        self.chain = []
        self.current_transactions = []
        self.new_block(previous_hash='1', proof=100)  # 创世区块
    def new_block(self, proof, previous_hash=None):
        block = {
            'index': len(self.chain) + 1,
            'timestamp': time(),
            'transactions': self.current_transactions,
            'proof': proof,
            'previous_hash': previous_hash or self.hash(self.chain[-1]),
        }
        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]
# 实例化Blockchain
blockchain = Blockchain()
# 创建一个新交易
blockchain.new_transaction(sender="Alice", recipient="Bob", amount=100)
# 挖掘一个新区块
blockchain.new_block(proof=12345)
print(blockchain.chain)

pip install ecdsa

from ecdsa import SigningKey, SECP256k1
# 生成ECDSA密钥对
sk = SigningKey.generate(curve=SECP256k1)  # 私钥
vk = sk.verifying_key  # 公钥
private_key = sk.to_string().hex()
public_key = vk.to_string().hex()
print(f"Private Key: {private_key}")
print(f"Public Key: {public_key}")

message = "Alice pays Bob 1 BTC"
signature = sk.sign(message.encode()).hex()
print(f"Message: {message}")
print(f"Signature: {signature}")

from ecdsa import VerifyingKey
# 将公钥和签名转换回相应格式
vk = VerifyingKey.from_string(bytes.fromhex(public_key), curve=SECP256k1)
signature_bytes = bytes.fromhex(signature)
# 验证签名
try:
    is_valid = vk.verify(signature_bytes, message.encode())
    print("Signature is valid." if is_valid else "Signature is invalid.")
except Exception as e:
    print(f"Signature verification failed: {str(e)}")

pip install web3

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
contract SimpleToken {
    event Transfer(address indexed from, address indexed to, uint256 value);
    // 假设的代币转移函数
    function transfer(address _to, uint256 _value) external {
        // ...执行转移逻辑
        emit Transfer(msg.sender, _to, _value);
    }
}

from web3 import Web3
# 使用Infura的WebSocket服务连接到以太坊主网络
w3 = Web3(Web3.WebsocketProvider('wss://mainnet.infura.io/ws/v3/YOUR_INFURA_PROJECT_ID'))
# 假设合约地址和ABI
contract_address = '0xYourContractAddress'
contract_abi = json.loads('''[{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"from","type":"address"},{"indexed":true,"internalType":"address","name":"to","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Transfer","type":"event"}]''')
# 创建合约对象
contract = w3.eth.contract(address=contract_address, abi=contract_abi)
# 创建事件过滤器
transfer_event_filter = contract.events.Transfer.createFilter(fromBlock='latest')
print("Listening for Transfer events...")
while True:
    # 检查新的事件
    for event in transfer_event_filter.get_new_entries():
        handle_event(event)
    time.sleep(10)
def handle_event(event):
    print(f"New Transfer event:\n From: {event['args']['from']}\n To: {event['args']['to']}\n Value: {event['args']['value']} tokens")

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
contract SimpleStorage {
    uint storedData;
    constructor(uint initialValue) {
        storedData = initialValue;
    }
    function setStoredData(uint x) public {
        storedData = x;
    }
    function getStoredData() public view returns (uint) {
        return storedData;
    }
}

pip install web3

from web3 import Web3
import json
# 连接到以太坊节点
infura_url = 'https://mainnet.infura.io/v3/YOUR_INFURA_PROJECT_ID'
w3 = Web3(Web3.HTTPProvider(infura_url))
# 确认连接成功
if w3.isConnected():
    print("Connected to Ethereum network")
# 智能合约ABI和地址
contract_abi = json.loads('[YOUR_CONTRACT_ABI_HERE]')
contract_address = 'YOUR_CONTRACT_ADDRESS_HERE'
# 创建智能合约对象
contract = w3.eth.contract(address=contract_address, abi=contract_abi)
# 调用合约的getStoredData函数
stored_data = contract.functions.getStoredData().call()
print(f"The stored data is: {stored_data}")