python-geth

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...with my dissertation. It is only 11 questions. As this package is part of my thesis it would be much appreciated if you spent a few moments on filling out these 11 anonymous questions. Thanks!

PyGeth

PyGeth is a Python library for a quick setup of an Ethereum blockchain using Geth and for fast prototyping of contracts with truffle.

Installation

Prerequisites

To be able to run this package, please install Geth and Npm (5.2.0 or higher) and add them to your Path. Note: This has solely been tested on Windows.

Use the package manager pip to install python-geth.

pip install python-geth

Usage

Node

from python_geth.node import Node

node1 = Node(datadir="C:\\Users\\macutko\\Desktop\\node01")
node1.start_node()

This creates a geth node that allows interaction with it via the web3 library.

node1.w3.geth.miner.start(1)

To add a node on the chain do as follows. It requires the same genesis file.

node2 = Node(datadir="C:\\Users\\macutko\\Desktop\\node02", genesis_file="C:\\Users\\macutko\\Desktop\\node01\\config\\genesisjson")
node2.start_node()
node1.add_node(node2.w3.geth.admin.node_info()['enode'])

Contracts

To be able to quickly deploy contracts and interact with them first configure truffle.

node1.configure_truffle()

To deploy a contract unlock an account, create a Contract Interface instance and deploy a contract. highly recommended to wrap deployment into a try and accept block. This is to prevent zombie processes.

account, password = node1.get_first_account()
node1.w3.geth.personal.unlock_account(account, password)

CI = ContractInterface(w3=node1.w3, datadir="C:\\Users\\macutko\\Desktop\\node01")
try:
    m_con = CI.deploy_contract(contract_file="C:\\Users\\macutko\\Desktop\\GUID.sol",constructor_params=['2265072m'])[0]
except:
    node1.stop_node()

Example Contract

Example contract:

pragma solidity ^0.4.24;

contract HelloWorld {

    string saySomething;

    constructor() public  {
        saySomething = "Hello World!";
    }

    function speak() public constant returns(string itSays) {
        return saySomething;
    }

    function saySomethingElse(string newSaying) public  returns(bool success) {
        saySomething = newSaying;
        return true;
    }

}

After deploying, to get the saySomething variable.

print(m_con.functions.speack.call())

And to set a new message.

tx_hash = m_con.functions.saySomethingElse("Not Hello World").transact()
tx_receipt = CI.w3.eth.waitForTransactionReceipt(tx_hash)

Pipeline

• BUG: Fix the start of an already created node
• TEST:Connection from different device

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

MIT