Python Node and SDK for the NEO blockchain
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neo-python

Python Node and SDK for the NEO blockchain.

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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
  • NEP-7 and NEP-8 support
  • RPC Client
  • RPC server
  • Notification Server ( for viewing transfers of NEP5 tokens )
  • Runtime.Log and Runtime.Notify event monitoring

What will it do

  • 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, @metachris or @ixje on the NEO Discord.
  • Pull requests welcome. Have a look at the issue list for ideas. You can help with wallet functionality, writing tests or documentation, or on any other feature you deem awesome.

Getting started

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

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

Docker

Using Docker is another option to run neo-python. There are example Dockerfiles provided in the /docker folder, and we have an image on Docker hub, tagged after the neo-python releases: https://hub.docker.com/r/cityofzion/neo-python/

Native installation

Instructions on the system setup for neo-python:

LevelDB

OSX

brew install leveldb

Ubuntu/Debian 16.10+

Ubuntu starting at 16.10 supports Python 3.6+ in the official repositories.

First, ensure Ubuntu is fully up-to-date with this:

sudo apt-get update && sudo apt-get upgrade

You can install Python 3.7 and all the system dependencies like this:

sudo apt-get install python3.7 python3.7-dev python3.7-venv python3-pip libleveldb-dev libssl-dev g++

Or, you can install Python 3.6 and all the system dependencies like this:

sudo apt-get install python3.6 python3.6-dev python3.6-venv python3-pip libleveldb-dev libssl-dev g++

Older Ubuntu versions (eg. 16.04)

For older Ubuntu versions you'll need to use an external repository like Felix Krull's deadsnakes PPA at https://launchpad.net/~deadsnakes/+archive/ubuntu/ppa (read more here).

(The use of the third-party software links in this documentation is done at your own discretion and risk and with agreement that you will be solely responsible for any damage to your computer system or loss of data that results from such activities.)

apt-get install software-properties-common python-software-properties
add-apt-repository ppa:deadsnakes/ppa
apt-get update
apt-get install python3.6 python3.6-dev python3.6-venv python3-pip libleveldb-dev libssl-dev g++

Centos/Redhat/Fedora

# Install Python 3.6:
yum install -y centos-release-scl
yum install -y rh-python36
scl enable rh-python36 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

Currently, you should use the Linux subsystem with Ubuntu, or a Virtual Machine with Linux. You can find more information and a guide for setting up the Linux subsystem here.

Installing "Ubuntu" from Microsoft Store installs Ubuntu 16.04. You should install Ubuntu 18.04 from Microsoft Store found here: https://www.microsoft.com/en-us/p/ubuntu-1804/9n9tngvndl3q?activetab=pivot%3aoverviewtab

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

Python 3.6+

neo-python is compatible with Python 3.6 and later.

On *nix systems, install Python 3.6 or Python 3.7 via your package manager, or download an installation package from the official homepage.

Install

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.

  1. Install from Github:
git clone https://github.com/CityOfZion/neo-python.git
cd neo-python

# if you want to use the development branch, switch now
git checkout development

# create virtual environment using Python 3.7 and activate or skip to the next step for Python 3.6
python3.7 -m venv venv
source venv/bin/activate

# create virtual environment using Python 3.6 and activate
python3.6 -m venv venv
source venv/bin/activate

# install the package in an editable form
(venv) pip install wheel -e .
  1. Install from PyPi
# create project dir
mkdir myproject
cd myproject

# create virtual environment using Python 3.7 and activate or skip to the next step for Python 3.6
python3.7 -m venv venv
source venv/bin/activate

# create virtual environment using Python 3.6 and activate
python3.6 -m venv venv
source venv/bin/activate

(venv) pip install wheel neo-python

Running

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

np-prompt
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:

np-prompt
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>

Bootstrapping the Blockchain

If you use neo-python for the first time, you need to synchronize the blockchain, which may take a long time. Included in this project is the script np-bootstrap to automatically download a chain directory for you.

np-bootstrap Usage

$ np-bootstrap -h
usage: np-bootstrap [-h] [-m] [-c CONFIG] [-n] [-s] [--datadir DATADIR]

optional arguments:
  -h, --help            show this help message and exit
  -m, --mainnet         use MainNet instead of the default TestNet
  -c CONFIG, --config CONFIG
                        Use a specific config file
  -n, --notifications   Bootstrap notification database
  -s, --skipconfirm     Bypass warning about overwritting data in Chains/SC234
  --datadir DATADIR     Absolute path to use for database directories

Bootrapping Testnet

To bootstrap the testnet blockchain, run np-bootstrap, get a cup of coffee and wait. Then, bootstrap the testnet notifications database with np-bootstrap -n.

Bootstrapping Mainnet

To bootstrap the mainnet blockchain, run np-bootstrap -m and get 8 cups of coffee (9+ GB file). Then, bootstrap the mainnet notifications database with np-bootstrap -m -n.

Important: do not use the chain files from https://github.com/CityOfZion/awesome-neo.git, they will not work with neo-python.

Basic Wallet commands

create wallet {wallet_path}
open wallet {wallet_path}
wallet close

wallet (verbose)
wallet rebuild (start block)
wallet create_addr {number of addresses}
wallet delete_addr {addr}

export wif {address}
import wif {wif}

export nep2 {address}
import nep2 {nep2_encrypted_key}

send {assetId or name} {address} {amount} (--from-addr={addr}) (--fee={priority_fee}) (--owners=[{addr}, ...]) (--tx-attr=[{"usage": <value>,"data":"<remark>"}, ...])

For a complete list of commands use help.

Running on MainNet

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

$ np-prompt -h
usage: np-prompt [-h] [-m | -p [host] | --coznet | -c CONFIG]
                 [-t {dark,light}] [-v] [--datadir DATADIR] [--version]

optional arguments:
  -h, --help            show this help message and exit
  -m, --mainnet         Use MainNet instead of the default TestNet
  -p [host], --privnet [host]
                        Use a private net instead of the default TestNet,
                        optionally using a custom host (default: 127.0.0.1)
  --coznet              Use the CoZ network 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'
  -v, --verbose         Show smart-contract events by default
  --datadir DATADIR     Absolute path to use for database directories
  --maxpeers MAXPEERS   Max peers to use for P2P Joining
  --version             show program's version number and exit

Logging

Currently, np-prompt logs to prompt.log


Tests

Note we make use of a Blockchain fixture database (~15 MB). This file is not kept in the repo, but is 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


# run only neo-python tests
python -m unittest discover neo

# run only neo-boa tests
python -m unittest discover boa_test

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 and Docker Hub image
git push origin master development --tags

Troubleshooting

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

  • Double-check that you are using Python 3.6.x or Python 3.7.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

Donations

Accepted at ATEMNPSjRVvsXmaJW4ZYJBSVuJ6uR2mjQU