Using Python to write Ethereum smart contracts from basic knowledge to practical applications

Use Python to write Ethereum smart contract code.

What is Ethereum Smart Contract?.

The Ethereum smart contract is a self-executing protocol running on the blockchain that allows users to conduct trusted transactions without a third-party intermediary.

Once a smart contract is deployed to the Ethereum network, its logic and rules cannot be changed, thus ensuring the transparency and security of transactions.

Basic functions and features.

1. # Auto Execution #: Once the terms and conditions in the smart contract are met, they will be automatically executed without human intervention.

2. # Decentralization #: Smart contracts run on distributed ledgers, eliminating the need for central authority.

3. # Transparency #: All transaction records are public and can be viewed by anyone.

4. # Untamperable #: Once deployed, smart contracts cannot be modified or deleted.

Create, deploy and manage Ethereum smart contracts using Python.

Install the necessary tools.

First, we need to install some necessary tools and libraries, including web3.py(for interacting with Ethereum) and solcx(Solidity compiler).

pip install web3
pip install py-solc-x

Write Solidity smart contracts.

We will write a simple Solidity smart contract that allows the user to store and retrieve a string value.

solidity
// SimpleStorage.sol
pragma solidity ^0.8.0;

contract SimpleStorage {
    uint256 public storedData;

    function set(uint256 x) public {
        storedData = x;
    }

    function get() public view returns (uint256) {
        return storedData;
    }
}

Compile Solidity smart contracts.

Next, we use solcxTo compile this Solidity file.

from solcx import compile_standard, install_solc
import json

install_solc('0.8.0')

with open("SimpleStorage.sol", "r") as file:
    simple_storage_file = file.read()

compiled_sol = compile_standard({
    "language": "Solidity",
    "sources": {"SimpleStorage.sol": {"content": simple_storage_file}},
    "settings": {
        "outputSelection": {
            "*": {"*": ["abi", "metadata", "evm.bytecode", "evm.sourceMap"]}
        }
    },
})

with open("compiled_code.json", "w") as file:
    json.dump(compiled_sol, file)

Deploy smart contracts.

Now, we will use web3.pyTo deploy this smart contract to the Ethereum test network (such as Ropsten).

from web3 import Web3

# 连接到以太坊节点（这里使用Infura提供的Ropsten测试网络）
infura_url = 'https://ropsten.infura.io/v3/YOUR_INFURA_PROJECT_ID'
web3 = Web3(Web3.HTTPProvider(infura_url))

# 确保连接成功
assert web3.isConnected(), "Failed to connect to Ethereum network!"

# 设置账户信息（请替换为你的账户地址和私钥）
account = web3.eth.account.privateKeyToAccount('YOUR_PRIVATE_KEY')
web3.eth.defaultAccount = account.address

# 获取编译后的合约字节码和ABI
with open("compiled_code.json", "r") as file:
    compiled_sol = json.load(file)
    contract_abi = compiled_sol['contracts']['SimpleStorage.sol']['SimpleStorage']['abi']
    contract_bytecode = compiled_sol['contracts']['SimpleStorage.sol']['SimpleStorage']['evm']['bytecode']['object']

# 部署合约
SimpleStorage = web3.eth.contract(abi=contract_abi, bytecode=contract_bytecode)
tx_hash = SimpleStorage.constructor().transact({'from': account.address})
tx_receipt = web3.eth.waitForTransactionReceipt(tx_hash)

# 获取合约地址
simple_storage = web3.eth.contract(address=tx_receipt.contractAddress, abi=contract_abi)
print(f'Contract deployed at address: {simple_storage.address}')

Interact with smart contracts.

Now we can use Python to interact with deployed smart contracts.

Here's how to call the contract setSumgetMethod.

# 设置存储的值
tx_hash = simple_storage.functions.set(123).transact({'from': account.address})
web3.eth.waitForTransactionReceipt(tx_hash)
print('Value set to 123')

# 获取存储的值
stored_value = simple_storage.functions.get().call()
print(f'Stored value is: {stored_value}')

Key technologies and tools.

Solidity programming language.

Solidity is a high-level programming language designed specifically for writing Ethereum smart contracts.

It draws on some features of JavaScript, C + + and Python, allowing developers to quickly get started and write complex smart contracts.

Truffle framework.

Truffle is a development framework for developing, testing and deploying Ethereum smart contracts.

It provides a complete tool chain, including automated testing, scripted deployment, etc., which greatly simplifies the development process of smart contracts.

npm install -g truffle
truffle init

You can then create and deploy smart contracts and test and debug them using command-line tools provided by Truffle.

Successful case sharing.

Many well-known projects have successfully used Python and Ethereum smart contract technology.

For example, decentralized financial (DeFi) platforms such as Compound and Uniswap use smart contracts to enable decentralized asset lending and trading.

The success of these projects proves the powerful application of Python in the development of Ethereum smart contracts.

Challenges and solutions.

Although Python has many advantages in Ethereum smart contract development, there are also some challenges, such as performance issues, immaturity of development tools, etc.

To overcome these challenges, we can take the following measures: 1. # Optimized performance #: Improve the execution efficiency of smart contracts by reducing unnecessary computing and storage operations.

2. # Use mature development tools #: Choose community-proven development tools and frameworks such as Truffle and Ganache to improve development efficiency and code quality.

3. # Continuous learning and updating knowledge #: With the continuous development of Ethereum and smart contract technology, keep the focus and learning on new technologies and new tools to adapt to the changing technology environment.

Summarize.

Through the introduction of this article, you should already understand the basic steps and key techniques of how to write Ethereum smart contracts using Python.

From basic knowledge to practical applications, we detailed the functions and features of smart contracts, and how to use Python to create, deploy and manage smart contracts.

We also discussed some key technologies and tools, and demonstrated the application effect of Python in the development of Ethereum smart contracts through practical cases.

I hope this article can help you deeply understand and master the practical application of Python in Ethereum smart contract development, and improve your skill level.