ontospy 1.0.0b2

A Python project for working with RDF/OWL ontologies

RDFLIb-based Python toolkit for inspecting ontologies on the Semantic Web.

Description

Originally, I developed this script in order to get the hang of the Python RDFLib library (note: it was previously called OntoInspector and hosted on BitBucket). RDFLib provides a number of useful primitives for working with RDF graphs; however it lacks an API aimed at interrogating and modifying a graph based on its defined schema - aka the ontology.

OntosPy allows you to extract all the schema information from an RDFS/OWL ontology, inspect it and use it query a corresponding knowledge base.

The basic worflow is simple: load an ontology by instantiating the Ontology class; you get back an object that lets you interrogate the RDFS/OWL schema. That’s all!

Ps: the library can be used in standalone mode too.

Example

Import ontospy and instantiate the Ontology object with the FOAF ontology:

In [1]: from ontospy.ontospy import *

In [2]: onto = Ontology("http://xmlns.com/foaf/spec/20100809.rdf")

In [3]: onto.toplayer
Out[3]:
[rdflib.URIRef('http://xmlns.com/foaf/0.1/Agent'),
 rdflib.URIRef('http://www.w3.org/2000/01/rdf-schema#Class'),
 rdflib.URIRef('http://www.w3.org/2004/02/skos/core#Concept'),
 rdflib.URIRef('http://xmlns.com/foaf/0.1/Document'),
 rdflib.URIRef('http://xmlns.com/foaf/0.1/LabelProperty'),
 rdflib.URIRef('http://www.w3.org/2000/01/rdf-schema#Literal'),
 rdflib.URIRef('http://www.w3.org/2000/10/swap/pim/contact#Person'),
 rdflib.URIRef('http://xmlns.com/foaf/0.1/Project'),
 rdflib.URIRef('http://www.w3.org/2003/01/geo/wgs84_pos#SpatialThing'),
 rdflib.URIRef('http://www.w3.org/2002/07/owl#Thing')]

In [4]: onto.printClassTree()
foaf:Agent
----foaf:Group
----foaf:Organization
----foaf:Person
rdfs:Class
http://www.w3.org/2004/02/skos/core#Concept
foaf:Document
----foaf:Image
----foaf:PersonalProfileDocument
foaf:LabelProperty
rdfs:Literal
http://www.w3.org/2000/10/swap/pim/contact#Person
----foaf:Person
foaf:Project
http://www.w3.org/2003/01/geo/wgs84_pos#SpatialThing
----foaf:Person
owl:Thing
----foaf:OnlineAccount
--------foaf:OnlineChatAccount
--------foaf:OnlineEcommerceAccount
--------foaf:OnlineGamingAccount


In [5]: document = onto.classFind("document")

In [6]: document
Out[6]:
[rdflib.URIRef('http://xmlns.com/foaf/0.1/Document'),
 rdflib.URIRef('http://xmlns.com/foaf/0.1/PersonalProfileDocument')]

In [7]: document = document[0]

In [8]: document
Out[8]: rdflib.URIRef('http://xmlns.com/foaf/0.1/Document')

In [9]: onto.classAllSubs(document)
Out[9]:
[rdflib.URIRef('http://xmlns.com/foaf/0.1/Image'),
 rdflib.URIRef('http://xmlns.com/foaf/0.1/PersonalProfileDocument')]

In [10]: onto.classAllSupers(document)
Out[10]: []

In [11]: onto.entityComment(document)
Out[11]: rdflib.Literal('A document.', language=None, datatype=None)

Sketch.py: bootstrapping a Turtle model

The library includes a little utility called sketch.py.

This is meant to be used from the command line (Tip: make this file executable: chmod +x sketch.py) and essentially loads up an interactive python environment where you can quickly sketch out an RDF model via the Turtle syntax:

[michele.pasin]@here:~/code/python>sketch.py
Good morning. Ready to Turtle away. Type docs() for help.
In [1]: docs()

====Sketch v 0.2====

add()  ==> add statements to the graph
...........SHORTCUTS:
...........'class' = owl:Class
...........'sub' = rdfs:subClassOf
...........TURTLE SYNTAX:  http://www.w3.org/TR/turtle/

show() ==> shows the graph. Can take an OPTIONAL argument for the format.
...........eg one of['xml', 'n3', 'turtle', 'nt', 'pretty-xml', dot']

clear()  ==> clears the graph
...........all triples are removed

omnigraffle() ==> creates a dot file and opens it with omnigraffle
...........First you must set Omingraffle as your system default app for dot files!

quit() ==> exit

====Have fun!====


In [2]: add()
Multi-line input. Enter ### when finished.
:person a class
:mike a :person
:person sub :agent
:organization sub :agent
:worksIn rdfs:domain :person
:worksIn rdfs:range :organization
:mike :worksIn :DamageInc
:DamageInc a :organization

In [3]: show()
@prefix : <http://this.sketch#> .
@prefix bibo: <http://purl.org/ontology/bibo/> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix npg: <http://ns.nature.com/terms/> .
@prefix npgg: <http://ns.nature.com/graphs/> .
@prefix npgx: <http://ns.nature.com/extensions/> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix xml: <http://www.w3.org/XML/1998/namespace> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

:mike a :person ;
    :worksIn :DamageInc .

:worksIn rdfs:domain :person ;
    rdfs:range :organization .

:DamageInc a :organization .

:organization rdfs:subClassOf :agent .

:person a owl:Class ;
    rdfs:subClassOf :agent .



In [4]: show("xml")
<?xml version="1.0" encoding="UTF-8"?>
<rdf:RDF
   xmlns="http://this.sketch#"
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
>
  <rdf:Description rdf:about="http://this.sketch#mike">
    <rdf:type rdf:resource="http://this.sketch#person"/>
    <worksIn rdf:resource="http://this.sketch#DamageInc"/>
  </rdf:Description>
  <rdf:Description rdf:about="http://this.sketch#organization">
    <rdfs:subClassOf rdf:resource="http://this.sketch#agent"/>
  </rdf:Description>
  <rdf:Description rdf:about="http://this.sketch#DamageInc">
    <rdf:type rdf:resource="http://this.sketch#organization"/>
  </rdf:Description>
  <rdf:Description rdf:about="http://this.sketch#person">
    <rdf:type rdf:resource="http://www.w3.org/2002/07/owl#Class"/>
    <rdfs:subClassOf rdf:resource="http://this.sketch#agent"/>
  </rdf:Description>
  <rdf:Description rdf:about="http://this.sketch#worksIn">
    <rdfs:domain rdf:resource="http://this.sketch#person"/>
    <rdfs:range rdf:resource="http://this.sketch#organization"/>
  </rdf:Description>
</rdf:RDF>

In [5]: omnigraffle()
### saves a dot file and tries to open it with your default editor
### if you're on a mac and have omnigraffle - that could be the one!

In [6]: quit()