reasonable (Python bindings)

Python bindings for Reasonable — a reasonably fast OWL 2 RL reasoner implemented in Rust. This package exposes a small, typed API over rdflib terms to run materialization on RDF graphs or files.

Quick Usage

Load from files (Turtle/N3) and materialize inferred triples:

import reasonable

r = reasonable.PyReasoner()
r.load_file("../example_models/ontologies/Brick.n3")
r.load_file("../example_models/small1.n3")
out = r.reason()  # list[tuple[rdflib.term.Node, Node, Node]]
print(len(out))

Reason directly over an rdflib Graph:

import rdflib
import reasonable
from rdflib.term import URIRef

g = rdflib.Graph()
g.add((URIRef("urn:s"), URIRef("urn:p"), URIRef("urn:o")))

r = reasonable.PyReasoner()
r.from_graph(g)
triples = r.reason()

# Optionally collect into a new Graph
g_out = rdflib.Graph()
for s, p, o in triples:
    g_out.add((s, p, o))
print(len(g_out))

Incremental Reasoning with Retraction

Use update_graph() to replace the reasoner's base triples when your graph changes. The reasoner automatically computes a diff and selects incremental materialization (additions only) or full re-materialization (if removals detected):

import rdflib
import reasonable
from rdflib import URIRef, RDF

ontology = rdflib.Graph()
ontology.parse("my_ontology.ttl")

data = rdflib.Graph()
data.add((URIRef("urn:sensor1"), RDF.type, URIRef("urn:TemperatureSensor")))

r = reasonable.PyReasoner()
r.from_graph(ontology + data)
triples = r.reason()  # full materialization

# Later, data changes...
data.remove((URIRef("urn:sensor1"), RDF.type, URIRef("urn:TemperatureSensor")))
data.add((URIRef("urn:sensor2"), RDF.type, URIRef("urn:HumiditySensor")))

r.update_graph(ontology + data)  # replaces base, auto-detects diff
triples = r.reason()             # full re-mat (removals detected)

Install

• Runtime dependency: rdflib
• If you have a prebuilt wheel: pip install dist/reasonable-*.whl
• Build from source (see below) if no wheel is available for your platform.

Developer Install (from source)

Using uv (recommended for local dev):

cd python
# Install project dependencies (including dev tools) into a managed venv
uv sync --group dev

# Build and develop-install the extension module
uv run maturin develop -b pyo3 --release

# Sanity check
uv run python -c "import reasonable; print(reasonable.__version__)"

Without uv (system/venv):

cd python
python -m venv .venv && . .venv/bin/activate  # or use your env
pip install -U maturin
maturin develop -b pyo3 --release
python -c "import reasonable; print(reasonable.__version__)"

API Reference

• reasonable.PyReasoner()
  • load_file(path: str) -> None
    • Load triples from a Turtle or N3 file. Appends to existing base triples. Raises OSError on missing/invalid paths.
  • from_graph(graph_or_iterable) -> None
    • Appends triples from an rdflib Graph (or any iterable of 3-tuples) to the base. Use update_graph() instead if you need retraction support.
  • update_graph(graph_or_iterable) -> bool
    • Replaces the base triples with the contents of the given graph. Computes a diff against the current base: if only additions are found, the next reason() uses incremental materialization; if any removals are detected, it triggers a full re-materialization. Returns True if removals were detected, False otherwise.
  • reason() -> list[tuple[Node, Node, Node]]
    • Runs OWL 2 RL materialization and returns all known triples (base + inferred) as rdflib nodes. After the first call, subsequent calls are incremental (only processing newly added triples) unless removals were detected via update_graph().
  • reason_full() -> list[tuple[Node, Node, Node]]
    • Forces a full re-materialization from base triples, ignoring any incremental state. Equivalent to clear() followed by reason().
  • clear() -> None
    • Resets all inferred state while keeping base triples. The next reason() call will perform a full re-materialization.
  • get_base_triples() -> list[tuple[Node, Node, Node]]
    • Returns the current base (non-inferred) triples as rdflib nodes. Useful for debugging.

Building Wheels

Build release wheels into dist/:

cd python
uv run maturin build --release --out dist

Install the built wheel:

pip install dist/reasonable-*.whl

Requirements

• Python 3.9+ (ABI3, built with pyo3/abi3-py39)
• Rust toolchain (rustup, cargo) for local builds
• maturin for building wheels
• rdflib (runtime dependency)

Testing

Run the Python test suite (uses pytest and rdflib):

cd python
uv run pytest -q

Alternatively, with a local venv:

cd python
pip install -U maturin pytest rdflib
maturin develop -b pyo3 --release
pytest -q

Compatibility Notes

• Python: 3.9+ is required due to the ABI3 setting in the Rust crate (abi3-py39).
• Platforms: macOS, Linux, and Windows are supported by PyO3/maturin; building from source requires a Rust toolchain.

Troubleshooting

• ModuleNotFoundError: No module named 'reasonable':
  • Ensure you ran maturin develop in the same environment you’re importing from.
• Build/link errors on macOS (Xcode/SDK):
  • Install Command Line Tools: xcode-select --install.
• OSError when calling load_file(...):
  • Check the path and file format (Turtle/N3). Use absolute paths when in doubt.

Contributing (Python bindings)

• Keep tests under python/tests/ minimal and representative. Prefer inputs from example_models/.
• Format/lint Python with standard tooling; Rust code follows cargo fmt/cargo clippy.
• For broader project info (CLI, library, benchmarks), see the repository root README.md.