The Py2neo Handbook

Py2neo is a client library and toolkit for working with Neo4j from within Python applications and from the command line. The library supports both Bolt and HTTP and provides a high level API, an OGM, admin tools, an interactive console, a Cypher lexer for Pygments, and many other bells and whistles. Unlike previous releases, Py2neo does not require an HTTP-enabled server and can work entirely through Bolt.

When considering whether to use py2neo or the official Python Driver for Neo4j, there is a trade-off to be made. Py2neo offers a larger surface, with both a higher level API and an OGM, but the official driver provides mechanisms to work with clusters, such as automatic retries. If you are new to Neo4j, need an OGM, do not want to learn Cypher immediately, or require data science integrations, py2neo may be the better choice. If you are building a high-availability Enterprise application, or are using a cluster, you likely need the official driver.

Releases & Versioning

As of 2020, py2neo has switched to Calendar Versioning, using a scheme of YYYY.N.M. Here, N is an incrementing zero-based number for each year, and M is a revision within that version (also zero-based).

No compatibility guarantees are given between versions, but as a general rule, a change in M should require little-to-no work within client applications, whereas a change in N may require some work. A change to the year is likely to require a more significant amount of work to upgrade.

Note that py2neo is developed on a rolling basis, so patches are not made to old versions. Users will instead need to install the latest release to adopt bug fixes.

Installation

To install the latest release of py2neo, simply use:

$ pip install --upgrade py2neo

To install the latest stable code from the GitHub master branch, use:

$ pip install git+https://github.com/technige/py2neo.git@master#egg=py2neo

Requirements

The following versions of Python and Neo4j are supported:

  • Python 2.7 / 3.5 / 3.6 / 3.7 / 3.8
  • Neo4j 3.4 / 3.5 / 4.0 / 4.1 (the latest point release of each version is recommended)

While either Neo4j Community or Enterprise edition may be used, py2neo does not yet fully support all Enterprise-only features, such as Causal Clustering. Py2neo does however provide support for the multi-database functionality added in Neo4j 4.0. More about this can be found in the documentation for the Graph class.

Note that Py2neo is developed and tested under Linux using standard CPython distributions. While other operating systems and Python distributions may work, support for these is not available.

Core Graph API

Py2neo consists of several layers of API, and at the heart of those is the Graph API. This has evolved from the original, foundational API included with early versions of the library, and remains relevant for general purpose use today. The backbone of this API is the Graph class, which represents a graph database exposed by a Neo4j service running on a single instance or cluster. The service itself is represented by a GraphService object.

Node and Relationship objects are also key to this API, both of which extend the Subgraph class. A comprehensive set of graph structure data types and operations are provided, allowing great flexibility in how graph data can be used.

Command Line Usage