example.py

#! /usr/bin/python

from py4j.java_gateway import JavaGateway, GatewayParameters

# connect to the java gateway of dl4python
gateway = JavaGateway()
#gateway = JavaGateway(gateway_parameters=GatewayParameters(port=25335))

# get a parser from OWL files to DL ontologies
# parser = gateway.getOWLParser(True)        # Use this version to simplify all names
parser = gateway.getOWLParser(False) # Use this version to use full IRIs of everything

# get a formatter to print in nice DL format
formatter = gateway.getSimpleDLFormatter()

print("Loading the ontology...")

# load an ontology from a file
ontology = parser.parseFile("pizza.owl")

print("Loaded the ontology!")

# Sometimes it can be convenient to have only binary conjunctions in your ontology.
# The following method call transforms all conjunctions to binary ones.
print("Converting to binary conjunctions")
gateway.convertToBinaryConjunctions(ontology)



# get the TBox axioms
tbox = ontology.tbox()
axioms = tbox.getAxioms()


print("These are the axioms in the TBox:")
for axiom in axioms:
    print(formatter.format(axiom))


# get all concepts occurring in the ontology
allConcepts = ontology.getSubConcepts()

print()
print("There are ",len(allConcepts), " concepts occurring in the ontology")
print("These are the concepts occurring in the ontology:")
print([formatter.format(x) for x in allConcepts])

conceptNames = ontology.getConceptNames()

print()
print("There are ", len(conceptNames), " concept names occurring in the ontology")
print("These are the concept names: ")
print([x.name() for x in conceptNames])


roleNames = ontology.getRoleNames()

print()
print("There are ", len(roleNames), " role names occurring in the ontology")
print("These are the role names: ")
print([x.name() for x in roleNames])


# access the type of axioms:
foundGCI = False
foundEquivalenceAxiom = False
print()
print("Looking for axiom types in EL")
for axiom in axioms:
    axiomType = axiom.getClass().getSimpleName() 
    #print(axiomType)
    if(not(foundGCI)
       and axiomType == "GeneralConceptInclusion"):
        print("I found a general concept inclusion:")
        print(formatter.format(axiom))
        print("The left hand side of the axiom is: ", formatter.format(axiom.lhs()))
        print("The right hand side of the axiom is: ", formatter.format(axiom.rhs()))
        print()
        foundGCI = True

    elif(not(foundEquivalenceAxiom)
         and axiomType == "EquivalenceAxiom"):
        print("I found an equivalence axiom:")
        print(formatter.format(axiom))
        print("The concepts made equivalent are: ")
        for concept in axiom.getConcepts():
            print(" - "+formatter.format(concept))
        print()
        foundEquivalenceAxiom = True

# accessing the relevant types of concepts:
foundConceptName=False
foundTop=False
foundExistential=False
foundConjunction=False
foundConceptTypes = set()

print()
print("Looking for concept types in EL")
for concept in allConcepts:
    conceptType = concept.getClass().getSimpleName()
    if(not(conceptType in foundConceptTypes)): 
        print(conceptType)
        foundConceptTypes.add(conceptType)
    if(not(foundConceptName) and conceptType == "ConceptName"):
        print("I found a concept name: "+formatter.format(concept))
        print()
        foundConceptName = True
    elif(not(foundTop) and conceptType == "TopConcept$"):
        print("I found the top concept: "+formatter.format(concept))
        print()
        foundTop = True
    elif(not(foundExistential) and conceptType == "ExistentialRoleRestriction"):
        print("I found an existential role restriction: "+formatter.format(concept))
        print("The role is: "+formatter.format(concept.role()))
        print("The filler is: "+formatter.format(concept.filler()))
        print()
        foundExistential = True
    elif(not(foundConjunction) and conceptType == "ConceptConjunction"):
        print("I found a conjunction: "+formatter.format(concept))
        print("The conjuncts are: ")
        for conjunct in concept.getConjuncts():
            print(" - "+formatter.format(conjunct))
        print()
        foundConjunction=True


# Creating EL concepts and axioms

elFactory = gateway.getELFactory()

conceptA = elFactory.getConceptName("A")
conceptB = elFactory.getConceptName("B")
conjunctionAB = elFactory.getConjunction(conceptA, conceptB)
role = elFactory.getRole("r")
existential = elFactory.getExistentialRoleRestriction(role,conjunctionAB)
top = elFactory.getTop()
conjunction2 = elFactory.getConjunction(top,existential)

gci = elFactory.getGCI(conjunctionAB,conjunction2)

print()
print()
print("I made the following GCI:")
print(formatter.format(gci))


# Using the reasoners

elk = gateway.getELKReasoner()
hermit = gateway.getHermiTReasoner() # might the upper case T!

margherita = elFactory.getConceptName('"Margherita"')

print()
print("I am first testing ELK.")
elk.setOntology(ontology)
print()
print("According to ELK, Margherita has the following subsumers: ")
subsumers = elk.getSubsumers(margherita)
for concept in subsumers:
    print(" - ",formatter.format(concept))
print("(",len(subsumers)," in total)")
print()
print("I can also classify the ontology with ELK.")
classificationResult = elk.classify()
print("But I am not printing the result, because that would be too much stuff (it is a dictionary)")
print()

print()
print("I am now testing HermiT.")
hermit.setOntology(ontology)
print()
print("According to HermiT, Margherita has the following subsumers: ")
subsumers = hermit.getSubsumers(margherita)
#print(subsumers)
for concept in subsumers:
    print(" - ",formatter.format(concept))
print("(",len(subsumers)," in total)")
print()
print("I can also classify the ontology with HermiT")
classificationResult = hermit.classify()
print("But I am not printing the result, because that would be too much stuff (it is a dictionary)")
print()