一、背景

web3.py是一個(gè)用于與以太坊交互的 Python 庫(kù)。
它常見(jiàn)于去中心化應(yīng)用程序 (dapps)中，幫助發(fā)送交易、與智能合約交互、讀取塊數(shù)據(jù)以及各種其他用例。
最初的 API 源自Web3.js Javascript API，但后來(lái)不斷發(fā)展以滿足 Python 開(kāi)發(fā)人員的需求和物質(zhì)享受。

本人在合約審計(jì)于模糊測(cè)試中需要驗(yàn)證一些基礎(chǔ)信息，學(xué)習(xí)了一下

pip install web3

web3開(kāi)發(fā)文檔 https://web3py.readthedocs.io/en/stable/

二、基礎(chǔ)應(yīng)用

• 連接到以太坊測(cè)試節(jié)點(diǎn)

  from web3 import Web3
  from web3 import EthereumTesterProvider # 以太網(wǎng)測(cè)試程序提供程序
  
  創(chuàng)建區(qū)塊鏈鏈接器 鏈接到測(cè)試節(jié)點(diǎn)
  w3 = Web3(EthereumTesterProvider())
  建立web3鏈接
  w3.is_connected()
  

• 使用HTTPProvider和web3連接eth節(jié)點(diǎn)

  provider_url = 'https://mainnet.infura.io/v3/3c3793ddeca**********299afb1c2dc6458'
  w3 = Web3(Web3.HTTPProvider(provider_url))
  w3.is_connected()
  

• 獲取最新的塊信息

  latest_block = w3.eth.get_block('latest')
  

• 驗(yàn)證智能合約地址是否有效

  is_addr = w3.is_address('0x314ECf414b0987EAf8A3504915******91d24')
  

• 獲取錢(qián)包余額有多少eth

  wallet = w3.to_checksum_address('0x314ECf414b0987EAf8A3504915d*****1d24')
  print(w3.eth.get_balance(wallet))
  

• 將wei轉(zhuǎn)化成eth (wei 是eth最小單位)

  wei = w3.from_wei(111111111111111111111, 'ether')
  print(wei)
  

三、區(qū)塊鏈合約交互

• ABI 包含輸入函數(shù)名稱(chēng)變量
  ABI 對(duì)于每個(gè)智能合約都是唯一的，除非代碼完全一樣 abi = '[]'
  
  abi = '[{"inputs":[],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"owner","type":"address"},{"indexed":true,"internalType":"address","name":"spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"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"},{"inputs":[{"internalType":"address","name":"owner","type":"address"},{"internalType":"address","name":"spender","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"subtractedValue","type":"uint256"}],"name":"decreaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"addedValue","type":"uint256"}],"name":"increaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"sender","type":"address"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"}]'
  contract_address = '0xda141e275f46F9Df74b29AA3eCf7fF77Bc6781AB'
  

• 調(diào)用合同函數(shù)或訪問(wèn)合同變量文章來(lái)源地址http://www.zghlxwxcb.cn/news/detail-510512.html

  例如: contract_instance.functions.someFunction().call()
  

  contract_instance = w3.eth.contract(address=contract_address, abi=abi)
  result = contract_instance.functions.totalSupply().call()
  result = contract_instance.functions.symbol().call()
  print(result)
  

四、智能合約的編譯

from solcx import compile_source, compile_standard

# 指定安裝某個(gè)版本編譯器
# install_solc(version='latest')

# 編譯合約代碼 輸出abi、bin 字節(jié)碼
compile_solidity = compile_source(
    '''
    // SPDX-License-Identifier: GPL-3.0
    pragma solidity ^0.8.18;
    contract HelloWorld {
        string public message;
        constructor(){
            message = 'HelloWorld!';
        }
        function setMessage(string memory _message) public{
            message = _message;
        }
        function sayMessage() public view returns (string memory) {
            return message;
        }
    }
    ''',
    output_values=['abi', 'bin']
)

# 檢索合約接口 compile_solidity.popitem()
contract_id, contract_interface = compile_solidity.popitem()
# print(contract_id)                # 合約name
# print(contract_interface)         # 合約abi、bin
# print(contract_interface['abi'])  # 合約abi

python 與eth智能合約進(jìn)行交互

# 創(chuàng)建連接到以太坊測(cè)試器的Web3實(shí)例
w3 = Web3(Web3.EthereumTesterProvider())
# w3 = Web3(Web3.WebsocketProvider)

# 設(shè)置默認(rèn)賬戶為測(cè)試器中的第一個(gè)賬戶
# w3.eth.accounts 是以太坊測(cè)試器中已創(chuàng)建的賬戶列表。通過(guò) w3.eth.default_account = w3.eth.accounts[0]，將默認(rèn)賬戶設(shè)置為測(cè)試器中的第一個(gè)賬戶。
# 這意味著當(dāng)您發(fā)送交易或調(diào)用合約函數(shù)時(shí)，如果沒(méi)有顯式指定賬戶，將默認(rèn)使用 w3.eth.accounts[0] 作為交易的發(fā)送者

w3.eth.default_account = w3.eth.accounts[0]

# 合約的ABI和字節(jié)碼
abi = contract_interface['abi']
bytecode = contract_interface['bin']

# 創(chuàng)建合約實(shí)例
helloworld = w3.eth.contract(abi=abi, bytecode=bytecode)

# 發(fā)送合約構(gòu)造函數(shù)的交易
transaction_hash = helloworld.constructor().transact()
# print(transaction_hash)

# 等待交易收據(jù)
transaction_receipt = w3.eth.wait_for_transaction_receipt(transaction_hash=transaction_hash)
# print(transaction_receipt)
'''
blockHash: 交易所在區(qū)塊的哈希值。
blockNumber: 交易所在區(qū)塊的編號(hào)。
contractAddress: 如果交易創(chuàng)建了一個(gè)新的合約，該參數(shù)表示新合約的地址。如果交易不是創(chuàng)建合約的交易，則為一個(gè)空字符串。
cumulativeGasUsed: 該交易之前所有交易的累計(jì)消耗的燃?xì)饬俊?effectiveGasPrice: 交易的有效燃?xì)鈨r(jià)格。
from: 發(fā)送者（發(fā)送交易的賬戶地址）。
gasUsed: 該交易消耗的燃?xì)饬俊?logs: 交易產(chǎn)生的日志事件。
state_root: 交易執(zhí)行后的狀態(tài)樹(shù)根哈希。
status: 交易的執(zhí)行狀態(tài)，1表示成功，0表示失敗。
to: 交易的接收者地址。如果是創(chuàng)建合約的交易，則為一個(gè)空字符串。
transactionHash: 交易的哈希值。
transactionIndex: 交易在所在區(qū)塊的索引位置
# type: 交易類(lèi)型1表示普通交易，2表示合約創(chuàng)建交易
'''

# # 獲取合約對(duì)象
# helloworldContract = w3.eth.contract(address=transaction_receipt.contractAddress, abi=abi)
# print(helloworldContract) # 獲取合約對(duì)象
# # 調(diào)用合約中函數(shù)sayMessage
# print(helloworldContract.functions.sayMessage().call())
# # 調(diào)用合約中函數(shù)setMessage,修改一個(gè)值,下面獲取并沒(méi)有變化，需要我們重新部署，發(fā)起交易
# print(helloworldContract.functions.setMessage('BEY').call())
# # 發(fā)現(xiàn)并沒(méi)有變化
# print(helloworldContract.functions.sayMessage().call())
# # 重新調(diào)用合約構(gòu)造函數(shù)的交易
# bye_hash = helloworldContract.functions.setMessage('BEY').transact()
# print(bye_hash)
# # 等待交易收據(jù)
# bye_receipt = w3.eth.wait_for_transaction_receipt(transaction_hash=bye_hash)
# print(bye_receipt)
# # 重新構(gòu)造以后才會(huì)修改為bye
# print(helloworldContract.functions.sayMessage().call())
# # print(is_addr)

python 編譯智能合約

compiled_solidity = compile_standard({
    "language": "Solidity",
    "sources": {
        "SimpleNumber.sol": {
            # "content": contract_file
        }
    },
    "setting": {
        "outputSelection": {
            "*": {"*": ["abi", "metadata", "evm.bytecode", "evm.sourceMap"]}
        }
    }
},
    solc_version='0.8.12'
)

print(compiled_solidity)

# compiled_solidity: 編譯后的Solidity結(jié)合的結(jié)果
# language: Solidity合約的編程語(yǔ)言，這里是"Solidity"
# sources: Solidity源代碼文件的字典，這里只有一個(gè)源代碼文件"SimpleNumber.sol"
# setting: 編輯設(shè)置的字典，包選擇輸出
# outputSelection: 輸入選的字典，選包包括ABI、元數(shù)據(jù)、EVM字節(jié)碼和EVM源映像
# solc_version: Solidity編譯器的版本，這里是"0.8.12"

使用python 部署智能合約

provider_url = 'https://goerli.infura.io/v3/3c3793ddeca5********fb1c2dc6458'
w3 = Web3(Web3.HTTPProvider(provider_url))
w3.is_connected()

abi = compiled_solidity['contracts']['SimpleNumber.sol']['SimpleNumber']['abi']
bytecode = compiled_solidity['contracts']['SimpleNumber.sol']['SimpleNumber']['evm']['bytecode']['object']

SimpleNumber = w3.eth.contract(abi=abi, bytecode=bytecode)
transaction = SimpleNumber.constructor().build_transaction(
    {
        "gasPrice": w3.eth.gas_price,
        "chainId": 3,
        "from": "wallet 錢(qián)包地址 來(lái)自metamask賬戶",
        "nonce": w3.eth.get_block_transaction_count("wallet 錢(qián)包地址 來(lái)自metamask賬戶")

    }
)

metamask 添加網(wǎng)絡(luò) eth 測(cè)試網(wǎng)絡(luò)

sign_transaction = w3.eth.account.sign_transaction(transaction, private_key='私鑰')
print(sign_transaction)
transaction_hash = w3.eth.send_raw_transaction(sign_transaction.rawTransaction)
print(transaction_hash)
transaction_receipt2 = w3.eth.wait_for_transaction_receipt(transaction_hash)
print(transaction_receipt2)

在python 中與部署的智能合約交互

contract_instance = w3.eth.contract(address=transaction_receipt2.contractAddress, abi=abi)

contract_instance.functions.getStoreNumber().call()
contract_instance.functions.updateStoreNumber(200).call()

update_number_transaction = contract_instance.functions.updateStoreNumber(200).call().build_transaction(
    {
        "gasPrice": w3.eth.gas_price,
        "chainId": 3,
        "from": "wallet 錢(qián)包地址 來(lái)自metamask賬戶",
        "nonce": w3.eth.get_block_transaction_count("wallet 錢(qián)包地址 來(lái)自metamask賬戶") + 1 # 每次加1 不能重復(fù)使用 nonce
    }
)

sign_transaction3 = w3.eth.account.sign_transaction(update_number_transaction, private_key='私鑰')
print(sign_transaction3)
transaction_hash3 = w3.eth.send_raw_transaction(sign_transaction3.rawTransaction)
print(transaction_hash3)
transaction_receipt3 = w3.eth.wait_for_transaction_receipt(transaction_hash3)
print(transaction_receipt3)
# 此時(shí)進(jìn)行變化
contract_instance.functions.getStoreNumber().call()

# print(latest_block)
# print(w3.is_connected())
# print(Web3)
# print(EthereumTesterProvider)

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