AllegroGraph Python API

The AllegroGraph Python API offers convenient and efficient access to an AllegroGraph server from a Python-based application. This API provides methods for creating, querying and maintaining RDF data, and for managing the stored triples. The AllegroGraph Python API deliberately emulates the Eclipse RDF4J (formerly Aduna Sesame) API to make it easier to migrate from RDF4J to AllegroGraph. The AllegroGraph Python API has also been extended in ways that make it easier and more intuitive than the RDF4J API.

Requirements

Python versions >=3.8,<=3.12 are supported. The installation method described here uses the pip package manager. On some systems this might require installing an additional package (e.g. python-pip on RHEL/CentOS systems). All third-party libraries used by the Python client will be downloaded automatically during installation.

Installation

Important: It is highly recommended to perform the install in a virtualenv environment.

The client can be installed from PyPI using the pip package manager:

pip install agraph-python

Alternatively, a distribution archive can be obtained from ftp://ftp.franz.com/pub/agraph/python-client and installed using pip:

pip install agraph-python-<VERSION>.tar.gz

Offline installation

If it is not possible to access PyPI from the target machine, the following steps should be taken:

• In a compatible environment with unrestricted network access run:

  pip wheel agraph-python
  

• This will generate a number of .whl files in the current directory. These files must be transferred to the target machine.

• On the target machine use this command to install:

  pip install --no-index --find-links=<DIR> agraph-python
  

  where <DIR> is the directory containing the .whl files generated in the previous step.

Install by conda

Using conda to install agraph-python is also supported:

conda create -n myenv python=3.10
conda activate myenv
conda install -y -c conda-forge -c franzinc agraph-python

Testing

To validate the installation make sure that you have access to an AllegroGraph server and run the following Python script:

from franz.openrdf.connect import ag_connect
    with ag_connect('repo', host='HOST', port='PORT',
                    user='USER', password='PASS') as conn:
    print (conn.size())

Substitute appropriate values for the HOST/PORT/USER/PASS placeholders. If the script runs successfully a new repository named repo will be created.

Proxy setup

It is possible to configure the AllegroGraph Python client to use a proxy for all its connection to the server. This can be achieved by setting the AGRAPH_PROXY environment variable, as in the following example:

# Create a SOCKS proxy for tunneling to an internal network
ssh -fN -D 1080 [email protected]
# Configure agraph-python to use this proxy
export AGRAPH_PROXY=socks://localhost:1080

The format of the AGRAPH_PROXY value is TYPE://HOST:PORT, where TYPE can be either http, socks4, socks5 or socks (a synonym for socks5). Note that if a SOCKS proxy is used, DNS lookups will be performed by the proxy server.

Unit tests

The Python client includes a suite of unit tests that can be run after installation. The tests are executed using the pytest framework and also use a few utilities from nose, so these two packages have to be installed. We also need the pytest-mock plugin:

pip install -e ".[test]"

The tests require a running AllegroGraph server instance. The configuration of this server is passed to the tests through environment variables:

# Host and port where the server can be reached. These values are the
# default, it is only necessary to define the variables below if your
# setup is different
export AGRAPH_HOST=localhost
export AGRAPH_PORT=10035

# Tests will create repositories in this catalog.
# It must exist on the server. Use "/" for the root catalog.
export AGRAPH_CATALOG=tests

# Login credentials for the AG server.
# The user must have superuser privileges.
export AGRAPH_USER=test

# Use a prompt to read the password
read -s -r -p "Password for user ${AGRAPH_USER}: " AGRAPH_PASSWORD
export AGRAPH_PASSWORD

To run the tests, type:

pytest --pyargs franz.openrdf.tests.tests --pyargs franz.openrdf.tests.newtests