neo-python

Python Node and SDK for the NEO blockchain.

Overview

What does it currently do

• This project aims to be a full port of the original C# NEO project
• Run a Python based P2P node
• Interactive CLI for configuring node and inspecting blockchain
• Build, deploy, and run smart contracts
• Runs smart contracts on the blockchain in a Python virtual machine
• Very basic Wallet functionality (not fully tested, please do not use on mainnet)
• NEP2 and NEP5 compliant wallet functionality
• RPC Client
• Runtime.Log and Runtime.Notify event monitoring

What will it do

• RPC server
• Consensus nodes
• More robust smart contract debugging and inspection

Documentation

The full documentation on how to install, configure and use neo-python can be found at Read The Docs.

Get help or give help

• Open a new issue if you encounter a problem.
• Or ping @localhuman or @metachris on the NEO Discord.
• Pull requests welcome. You can help with wallet functionality, writing tests or documentation, or on any other feature you deem awesome. All successful pull requests will be rewarded with one photo of a cat or kitten.

Getting started

neo-python has two System dependencies (everything else is covered with pip):

• LevelDB
• Python 3.5.4 (3.6 and up is currently not supported due to its byteplay3 dependency)

We have published a Youtube video to help get you started. There are many more videos under the CityOfZion Youtube channel, check them out.

LevelDB

OSX

brew install leveldb

Ubuntu/Debian

apt-get install libleveldb-dev python3.5-dev python3-pip python3-venv libssl-dev g++

Centos/Redhat/Fedora

This is a bit more tricky...

# Install Python 3.5:
yum install -y centos-release-scl
yum install -y rh-python35
scl enable rh-python35 bash

# Install dependencies:
yum install -y epel-release
yum install -y readline-devel leveldb-devel libffi-devel gcc-c++ redhat-rpm-config gcc python-devel openssl-devel

Windows

Help needed. Installing the Python package plyvel seems to require C++ compiler support tied to Visual Studio and libraries. Refer to documentation.

Python 3.5

neo-python is currently only compatible with Python 3.5 (due to its byteplay3 dependency).

On *nix systems, install Python 3.5 via your package manager, or download an installation package from the official homepage.

Virtual Environment

It is recommended to put all project dependencies into its own virtual environment, this way we don't pollute the global installation which could lead to version conflicts.

python3.5 -m venv venv
source venv/bin/activate

Now let's install neo-python's dependencies:

pip install -U setuptools pip wheel
pip install -e .

---

Running

Before running the neo-python CLI, make sure that the Chains directory in the project has the proper write permissions.

After installing requirements and activating the environment, there is an easy to use CLI (prompt.py) that starts the node and allows some basic interactivity.

python prompt.py
NEO cli. Type 'help' to get started

neo> state
Progress: 1054913 / 1237188

neo>

By default, the CLI connects to the TestNet (see below how to switch to MainNet or PrivNet).

Let's query for a block in the current server by hash or by block index:

python prompt.py
NEO cli. Type 'help' to get started

neo> block 122235
{
    "index": 122235,
    "script": "",
    "merkleroot": "1d5a895ea34509a83becb5d2f9391018a3f59d670d94a2c3f8deb509a07464bd",
    "previousblockhash": "98ae05cb68ab857659cc6c8379eb7ba68b57ef1f5317904c295341d82d0a1713",
    "tx": [
        "1d5a895ea34509a83becb5d2f9391018a3f59d670d94a2c3f8deb509a07464bd"
    ],
    "version": 0,
    "time": 1479110368,
    "hash": "74671375033f506325ef08d35632f74083cca564dc7ea6444c94d3b9dec3f61b",
    "consensus data": 16070047272025254767,
    "next_consensus": "59e75d652b5d3827bf04c165bbe9ef95cca4bf55"
}
neo>

Available Wallet commands

python prompt.py
NEO cli. Type 'help' to get started

neo> help

create wallet {wallet_path}
open wallet {wallet_path}

wallet { verbose } { rebuild } {rebuild BLOCK_HEIGHT}
export wif { ADDRESS }
import wif { WIF }

send { ASSET_ID } { ADDRESS } { AMOUNT }

Running on MainNet

To run the prompt on MainNet, you can use the CLI argument -m (eg. python prompt.py -m), for running on PrivNet you can use -p. Be sure to check out the details of the parameters:

$ python prompt.py -h
usage: prompt.py [-h] [-m] [-p] [-c CONFIG] [-t {dark,light}] [--version]

optional arguments:
  -h, --help            show this help message and exit
  -m, --mainnet         Use MainNet instead of the default TestNet
  -p, --privnet         Use PrivNet instead of the default TestNet
  -c CONFIG, --config CONFIG
                        Use a specific config file
  -t {dark,light}, --set-default-theme {dark,light}
                        Set the default theme to be loaded from the config
                        file. Default: 'dark'
  --version             show program's version number and exit

Logging

Currently, prompt.py logs to prompt.log

---

Tests

Note that some of the unit tests use a giant blockchain fixture database (~800MB). This file is not kept in the repo, but are downloaded the first time the tests are run, this can take some time (depending on the internet connection), but happens only once.

Useful commands

make lint
make test
make coverage
make docs

Updating the version number and releasing new versions of neo-python

This is a checklist for releasing a new version, which for now means:

1. Merging the changes from development into master
2. Setting the version from eg. 0.4.6-dev to 0.4.6 (which automatically created a tag/release)
3. On the dev branch, setting the version to the next patch, eg. 0.4.7-dev
4. Pushing master, development and the tags to GitHub

Make sure you are on the development branch and have all changes merged that you want to publish. Then follow these steps:

# Only in case you want to increase the version number again (eg. scope changed from patch to minor):
bumpversion --no-tag minor|major

# Update CHANGELOG.rst: make sure all changes are there and remove `-dev` from the version number
vi CHANGELOG.rst
git commit -m "Updated changelog for release" CHANGELOG.rst

# Merge development branch into master
git checkout master && git merge development

# Set the release version number and create the tag
bumpversion release

# Switch back into the development branch
git checkout development

# Increase patch number and add `-dev`
bumpversion --no-tag patch

# Push to GitHub, which also updates the PyPI package
git push && git push --tags

Troubleshooting

If you run into problems, check these things before ripping out your hair:

• Double-check that you are using Python 3.5.x
• Update the project dependencies (pip install -e .)
• If you encounter any problems, please take a look at the installation section in the docs, and if that doesn't help open an issue. We'll try to help.
• You can reach us on the NEO Discord, or simply file a GitHub issue.

License

• Open-source MIT.
• Main author is @localhuman.

Donations

Accepted at ATEMNPSjRVvsXmaJW4ZYJBSVuJ6uR2mjQU