Getting started

This guide shows how to install pyjelly and prepare your environment for use with RDFLib.

Installation

Install pyjelly from PyPI:

pip install pyjelly

pyjelly requires Python 3.9 or newer and works on all major platforms (Linux, macOS, Windows).

Usage with RDFLib

Once installed, pyjelly integrates with RDFLib automatically. You can immediately serialize and parse .jelly files using the standard RDFLib API.

Serialization

To serialize a graph to the Jelly format:

from rdflib import Graph
from pyjelly.serialize.streams import Stream
from pyjelly.options import StreamOptions, StreamTypes
from pyjelly import jelly

g = Graph()
g.parse("http://xmlns.com/foaf/spec/index.rdf")

options = StreamOptions(
    stream_types=StreamTypes(
        physical_type=jelly.PHYSICAL_STREAM_TYPE_TRIPLES,
        logical_type=jelly.LOGICAL_STREAM_TYPE_FLAT_TRIPLES,
    )
)
stream = Stream.from_options(options)

g.serialize(destination="foaf.jelly", format="jelly", stream=stream)

This creates a delimited Jelly stream using default options.

Parsing

To load RDF data from a .jelly file:

from rdflib import Graph

g = Graph()
g.parse("foaf.jelly")

print("Parsed triples:")
for s, p, o in g:
    print(f"{s} {p} {o}")

RDFLib will reconstruct the graph from the serialized Jelly stream.

File extension support

You can omit the format="jelly" parameter if the file ends in .jelly – RDFLib will auto-detect the format using pyjelly's entry point:

g.parse("foaf.jelly")  # format inferred automatically