OWLAPY

OWLAPY is a Python Framework for creating and manipulating OWL Ontologies.

Have a look at the Documentation.

Installation

Installation from Source

git clone https://github.com/dice-group/owlapy
conda create -n temp_owlapy python=3.10.13 --no-default-packages && conda activate temp_owlapy && pip3 install -e .

or

pip3 install owlapy

# To download RDF knowledge graphs
wget https://files.dice-research.org/projects/Ontolearn/KGs.zip -O ./KGs.zip && unzip KGs.zip
pytest -p no:warnings -x # Running 103 tests takes ~ 30 mins

Usage

In this example we start with a simple atomic class expression and move to some more complex ones and finally render and print the last of them in description logics syntax.

from owlapy.class_expression import OWLClass, OWLObjectIntersectionOf, OWLObjectSomeValuesFrom
from owlapy.owl_property import OWLObjectProperty
from owlapy import owl_expression_to_sparql, owl_expression_to_dl

# Create the male class
male = OWLClass("http://example.com/society#male")

# Create an object property using the iri as a string for 'hasChild' property.
hasChild = OWLObjectProperty("http://example.com/society#hasChild")

# Create an existential restrictions
hasChild_male = OWLObjectSomeValuesFrom(hasChild, male)

# Let's make it more complex by intersecting with another class
teacher = OWLClass("http://example.com/society#teacher")
teacher_that_hasChild_male = OWLObjectIntersectionOf([hasChild_male, teacher])

# You can render and print owl class expressions in description logics syntax (and vice-versa)
print(owl_expression_to_dl(teacher_that_hasChild_male))
# (∃ hasChild.male) ⊓ teacher
print(owl_expression_to_sparql(teacher_that_hasChild_male))
#  SELECT DISTINCT ?x WHERE {  ?x <http://example.com/society#hasChild> ?s_1 . ?s_1 a <http://example.com/society#male> . ?x a <http://example.com/society#teacher> .  } }

Every OWL object that can be used to classify individuals, is considered a class expression and inherits from OWLClassExpression class. In the above examples we have introduced 3 types of class expressions:

• OWLClass,
• OWLObjectSomeValuesFrom
• OWLObjectIntersectionOf.

Like we showed in this example, you can create all kinds of class expressions using the OWL objects in owlapy api.

Many axioms can automatically inferred with a selected reasoner

from owlapy.owlapi_adaptor import OWLAPIAdaptor

adaptor = OWLAPIAdaptor(path="KGs/Family/family-benchmark_rich_background.owl", name_reasoner="Pellet")
# Infer missing class assertions
adaptor.infer_and_save(output_path="KGs/Family/inferred_family-benchmark_rich_background.ttl",
                       output_format="ttl",
                       inference_types=[
                           "InferredClassAssertionAxiomGenerator",
                           "InferredEquivalentClassAxiomGenerator",
                           "InferredDisjointClassesAxiomGenerator",
                                        "InferredSubClassAxiomGenerator",
                                        "InferredInverseObjectPropertiesAxiomGenerator",
                                        "InferredEquivalentClassAxiomGenerator"])
adaptor.stopJVM()

Check also the examples folder.

How to cite

Currently, we are working on our manuscript describing our framework.