Skip to main content
Join the official Python Developers Survey 2018 and win valuable prizes: Start the survey!

A package for ontology-oriented programming in Python: load OWL 2.0 ontologies as Python objects, modify them, save them, and perform reasoning via HermiT. Includes an optimized RDF quadstore.

Project description

documentation download stats

Owlready2 is a module for ontology-oriented programming in Python 3, including an optimized RDF quadstore.

Owlready2 can:

  • Import OWL 2.0 ontologies in NTriples, RDF/XML or OWL/XML format.
  • Export OWL 2.0 ontologies to NTriples or RDF/XML.
  • Manipulates ontology classes, instances and properties transparently, as if they were normal Python objects.
  • Add Python methods to ontology classes.
  • Perform automatic classification of classes and instances, using the HermiT reasoner.
  • Tested up to 100 millions of RDF triples (but can potentially support more).
  • In addition, the quadstore is compatible with the RDFlib Python module, which can be used to perform SPARQL queries.

Owlready has been created by Jean-Baptiste Lamy at the LIMICS reseach lab. It is available under the GNU LGPL licence v3. If you use Owlready in scientific works, please cite the following article:

Lamy JB. Owlready: Ontology-oriented programming in Python with automatic classification and high level constructs for biomedical ontologies. Artificial Intelligence In Medicine 2017;80:11-28

In case of troubles, questions or comments, please use this Forum/Mailing list: http://owlready.8326.n8.nabble.com

What can I do with Owlready2?

Load an ontology from a local repository, or from Internet:

>>> from owlready2 import *
>>> onto_path.append("/path/to/your/local/ontology/repository")
>>> onto = get_ontology("http://www.lesfleursdunormal.fr/static/_downloads/pizza_onto.owl")
>>> onto.load()

Create new classes in the ontology, possibly mixing OWL constructs and Python methods:

>>> class NonVegetarianPizza(onto.Pizza):
...   equivalent_to = [
...     onto.Pizza
...   & ( onto.has_topping.some(onto.MeatTopping)
...     | onto.has_topping.some(onto.FishTopping)
...     ) ]
...   def eat(self): print("Beurk! I'm vegetarian!")

Access ontology class, and create new instances / individuals:

>>> onto.Pizza
pizza_onto.Pizza
>>> test_pizza = onto.Pizza("test_pizza_owl_identifier")
>>> test_pizza.has_topping = [ onto.CheeseTopping(),
...                            onto.TomatoTopping(),
...                            onto.MeatTopping  () ]

Export to RDF/XML file:

>>> test_onto.save()

Perform reasoning, and classify instances and classes:

>>> test_pizza.__class__
onto.Pizza

>>> # Execute HermiT and reparent instances and classes
>>> sync_reasoner()

>>> test_pizza.__class__
onto.NonVegetarianPizza
>>> test_pizza.eat()
Beurk! I'm vegetarian !

For more documentation, look at the doc/ directories in the source.

Changelog

version 1 - 0.2

  • Fix sync_reasonner and Hermit call under windows (thanks Clare Grasso)

version 1 - 0.3

  • Add warnings
  • Accepts ontologies files that do not ends with ‘.owl’
  • Fix a bug when loading ontologies including concept without a ‘#’ in their IRI

version 2 - 0.1

  • Full rewrite, including an optimized quadstore

version 2 - 0.2

  • Implement RDFXML parser and generator in Python (no longer use rapper or rdflib)
  • Property chain support
  • Add ntriples_diff.py utility
  • Bugfixes: - Fix breaklines in literal when exporting to NTriples

version 2 - 0.3

  • Add destroy_entity() global function
  • Greatly improve performance for individual creation
  • When searching, allow to use “*” as a jocker for any object
  • Bugfixes: - Fix nested intersections and unions - Fix boolean - Fix bug when removing parent properties - Fix parsing of rdf:ID - Fix multiple loading of the same ontology whose IRI is modified by OWL file, using an ontology alias table - Fix ClassConstruct.subclasses() - Check for properties with multiple incompatible classes (e.g. ObjectProperty and Annotation Property)

version 2 - 0.4

  • Add methods for querying the properties defined for a given individuals, the inverse properties and the relation instances (.get_properties(), .get_inverse_properties() and .get_relations())
  • Add .indirect() method to obtain indirect relations (considering subproperties, transivitity, symmetry and reflexibity)
  • search() now takes into account inheritance and inverse properties
  • search() now accepts ‘None’ for searching for entities without a given relation
  • Optimize ontology loading by recreating SQL index from scratch
  • Optimize SQL query for transitive quadstore queries, using RECURSIVE Sqlite3 statements
  • Optimize SQL query for obtaining the number of RDF triples (ie len(default_world.graph))
  • Add Artificial Intelligence In Medicine scientific article in doc and Readme
  • Bugfixes: - Fix properties loading when reusing an ontology from a disk-stored quadstore - Fix _inherited_property_value_restrictions() when complement (Not) is involved - Fix restrictions with cardinality - Fix doc on AllDisjoint / AllDifferent

version 2 - 0.5

  • Add individual/instance editor (require EditObj3, still largely untested)
  • Add support for hasSelf restriction
  • Optimize XML parsers
  • Check for cyclic subclass of/subproperty of, and show warning
  • PyPy 3 support (devel version of PyPy 3)
  • Bugfixes: - Fix search() for ‘*’ value on properties with inverse - Fix individual.annotation = “…” and property.annotation = “…” - Fix PlainLiteral annotation with no language specified - Fix doc for Creating classes dynamically - Fix loading ontologies with python_name annotations - Fix _inherited_property_value_restrictions when multiple is-a / equivalent-to are present - Align Python floats with xsd:double rather than xsd:decimal - Rename module ‘property’ as ‘prop’, to avoid name clash with Python’s ‘property()’ type

version 2 - 0.6

  • Add set_datatype_iri() global function for associating a Python datatype to an IRI
  • Add nquads ontology format (useful for debugging)
  • Add support for dir() on individuals
  • Add support for ontology using https: protocol (thanks Samourkasidis Argyrios)
  • Add observe module (for registering callback when the ontology is modified)
  • Improve docs
  • Bugfixes: - Align Python floats with xsd:decimal rather than xsd:double, finally, because decimal accepts int too - Fix Class.instances() so as it returns instances of subclasses (as indicated in the doc) - Fix direct assignation to Ontology.imported_ontologies - Fix a bug in reasoning, when adding deduced facts between one loaded and one non-loaded entity

version 2 - 0.7

  • Bugfixes: - Restore HermiT compiled with older Java compilator (higher compatibility)

version 2 - 0.8

  • Bugfixes: - REALLY restore HermiT compiled with older Java compilator (higher compatibility) - Fix search(prop = “value”) when value is a string and the ontology uses localized string

version 2 - 0.9

  • PostgresQL backend (in addition to SQLite3)
  • Add ‘exclusive = False’ option for SQLite3 backend (slower, but allows multiple uses)
  • Use unique index in sqlite3 quadstore on resources table
  • Optimize sqlite3 quadstore by caching IRI dict (5% faster)
  • Add == support for class construct
  • Add get_namespace() support on World
  • Add ‘existential restrictions as class properties’ feature
  • Bugfixes: - Fix imported ontologies - Fix saving ontologies in onto_path - Fix clear() on CallbackList - Fix bug in Class IRI in ontologies whose base IRI ends with a / - Fix imported ontologies in ontologies whose base IRI ends with a /

version 2 - 0.10

  • Add Ontology.metadata for adding/querying ontology metadata
  • Allows multiple individual creations with the same name/IRI, now returning the same individuals
  • Add OwlReadyInconsistentOntologyError and Word.inconsistent_classes()
  • Implement RDF/XML and OWL/XML parsing in Cython (25% speed boost for parsing)
  • Small optimization
  • Extend individual.prop.indirect() to include relations asserted at the class level
  • Add .query_owlready() method to RDF graph
  • Bugfixes: - Fix reasoning when obtaining classes equivalent to nothing - Fix World creation with backend parameters - Fix error when adding property at the class definition level - Fix loading of ontology files with no extension from onto_path - Fix properties defined with type ‘RDF Property’ and subproperty of ‘OWL Data/Object/Annotation Property’ - Support old SQLite3 versions that do not accept WITHOUT ROWID - Fix reference to undeclared entities (they were replaced by None, now by their IRI) - Fix loading and saving ontologies whose base IRI ends with / - Fix RDF query using string

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Filename, size & hash SHA256 hash help File type Python version Upload date
Owlready2-0.10.tar.gz (7.1 MB) Copy SHA256 hash SHA256 Source None Sep 17, 2018

Supported by

Elastic Elastic Search Pingdom Pingdom Monitoring Google Google BigQuery Sentry Sentry Error logging AWS AWS Cloud computing DataDog DataDog Monitoring Fastly Fastly CDN SignalFx SignalFx Supporter DigiCert DigiCert EV certificate StatusPage StatusPage Status page