Installation

You will need to install the libleveldb library. Install Python 3.6 to make sure you don’t run into any issues with your version of Python being different than the current maintainer’s version. Note that Python 3.5 and below are not supported.

You should install platform specific items before installing neo-python.

Platform Specific Instructions

Ubuntu/Debian 16.10+

Ubuntu starting at 16.10 supports Python 3.6 in the official repositories, and you can just install Python 3.6 and all the system dependencies like this:

apt-get install python3.6 python3.6-dev python3-pip python3-venv 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

The installation on the Windows operating system needs a set of unique steps and several common issues that might require troubleshooting, for this reason we dedicated a whole separate page for installing neo-python on windows.

If this is your operating system please check Installation (Windows)

OSX

brew install leveldb

Common issues on OSX

If you’re having an issue similar to this:

from ._plyvel import (  # noqa
ImportError: dlopen(neo-python/venv/lib/python3.6/site-packages/plyvel/_plyvel.cpython-35m-darwin.so, 2): Symbol not found: __ZN7leveldb2DB4OpenERKNS_7Options
ERKSsPPS0_
Referenced from: neo-python/venv/lib/python3.6/site-packages/plyvel/_plyvel.cpython-35m-darwin.so
Expected in: flat namespace

Solution: Update to plyvel 1.0.4: pip install -r requirements.txt


You may also encounter issues when installing the pycrypto module on OSX:

src/_fastmath.c:36:11: fatal error: 'gmp.h' file not found
# include <gmp.h>
          ^~~~~~~
330 warnings and 1 error generated.
error: command 'clang' failed with exit status 1

This may be fixed by installing the gmp library using homebrew and running pip install with the following commandline:

brew install gmp
CFLAGS='-mmacosx-version-min=10.7 -stdlib=libc++' pip install --no-use-wheel pycrypto --no-cache-dir --global-option=build_ext --global-option="-I/usr/local/Cellar/gmp/6.1.2/include/" --global-option="-L/usr/local/lib"

import scrypt / Reason: image not found

If you encounter an error like this:

import scrypt
File "/project_dir/venv/lib/python3.6/site-packages/scrypt.py", line 11, in
_scrypt = cdll.LoadLibrary(imp.find_module('_scrypt')[1])
File "/project_dir/venv/lib/python3.6/ctypes/init.py", line 429, in LoadLibrary
return self._dlltype(name)
File "/project_dir/venv/lib/python3.6/ctypes/init.py", line 351, in init
self._handle = _dlopen(self._name, mode)
OSError: dlopen(/project_dir/venv/lib/python3.6/site-packages/_scrypt.cpython-36m-darwin.so, 6): Library not loaded: /usr/local/opt/openssl/lib/libcrypto.1.0.0.dylib
Referenced from: /project_dir/venv/lib/python3.6/site-packages/_scrypt.cpython-36m-darwin.so
Reason: image not found

The solution probably is

brew reinstall openssl

Install from PyPi

The easiest way to install neo-python on your machine is to download it and install from PyPi using pip. First, we recommend you to create a virtual environment in order to isolate this installation from your system directories and then install it as you normally would do:

# create project dir
mkdir myproject
cd myproject

# create virtual environment and activate

python3.6 -m venv venv # this can also be python3 -m venv venv depending on your environment
source venv/bin/activate

(venv) pip install neo-python

Install from Git

Clone the repository at https://github.com/CityOfZion/neo-python/ and navigate into the project directory. Make a Python 3 virtual environment and activate it via

python3.6 -m venv venv
source venv/bin/activate

Then install the requirements via

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

Updating neo-python from Git

If you are updating neo-python with git pull, make sure you also update the dependencies with pip install -r requirements.txt.

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 bootstrap.py to automatically download a chain directory for you.

To bootstrap for testnet, run np-bootstrap, get a cup of coffee and wait.

To bootstrap for mainnet, use np-bootstrap -m and get 8 cups of coffee (3.3 GB file).