Lab: Even More OWL - Revision history

Sinoa: /* If You Have More Time */

2022-04-14T11:30:56Z

If You Have More Time

← Older revision		Revision as of 11:30, 14 April 2022
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	Try to use Hermit as in the lecture to infer additional triples.		Try to use Hermit as in the lecture to infer additional triples.
	IMPORANT: Neither Hermit/Pellet nor OWL-RL are able to reason with the full OWL-DL. But unlike OWL-RL, Owlready2 supports ~~reaosning~~ over many types of restrictions.		IMPORANT: Neither Hermit/Pellet nor OWL-RL are able to reason with the full OWL-DL. But unlike OWL-RL, Owlready2 supports reasoning over many types of restrictions.

	==Useful readings==		==Useful readings==
	* [https://pypi.org/project/Owlready2/ Project description] and ''What can I do with Owlready2?''		* [https://pypi.org/project/Owlready2/ Project description] and ''What can I do with Owlready2?''
	* [https://owlready2.readthedocs.io/en/latest/ Welcome to Owlready2's Documentation]		* [https://owlready2.readthedocs.io/en/latest/ Welcome to Owlready2's Documentation]

Sinoa: /* Code to get started */

2022-04-14T11:29:43Z

Code to get started

← Older revision		Revision as of 11:29, 14 April 2022
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	==Code to get started==		==Code to get started==
	(These need more testing!)		(These need more testing!)

			Load an ontology (will remember ontologies between sessions):
			<syntaxhighlight>
			BASE = 'http://info216.uib.no/owlready2-lab/'
			onto = get_ontology(BASE)
			</syntaxhighlight>

	Empty an ontology (otherwise owlready2 remembers ontologies between sessions!):		Empty an ontology (otherwise owlready2 remembers ontologies between sessions!):
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	print(g.serialize(format='ttl'))		print(g.serialize(format='ttl'))
	</syntaxhighlight>		</syntaxhighlight>


	==If You Have More Time==		==If You Have More Time==

Sinoa at 11:28, 14 April 2022

2022-04-14T11:28:08Z

← Older revision		Revision as of 11:28, 14 April 2022
Line 57:		Line 57:
	Empty an ontology (otherwise owlready2 remembers ontologies between sessions!):		Empty an ontology (otherwise owlready2 remembers ontologies between sessions!):
	<syntaxhighlight>		<syntaxhighlight>
			def clean_onto(onto):
			with onto:
			for ind in onto.individuals():
			destroy_entity(ind)
			for prop in onto.properties():
			destroy_entity(prop)
			for cls in onto.classes():
			destroy_entity(cls)
	</syntaxhighlight>		</syntaxhighlight>

	Print an ontology:		Print an ontology:
	<syntaxhighlight>		<syntaxhighlight>
			def onto2graph(onto):
			graph = Graph()
			onto.save('temp_owlready2/temp.nt', format='ntriples')
			graph.parse('temp_owlready2/temp.nt', format='ntriples')
			return graph

			def print_onto(onto):
			g = onto2graph(onto)
			g.bind('', Namespace(BASE))
			print(g.serialize(format='ttl'))
	</syntaxhighlight>		</syntaxhighlight>

	~~Print~~ an ontology without standard triples:		To print an ontology without standard triples (you must first define ''_empty_graph'' at the beginning of the program:
	<syntaxhighlight>		<syntaxhighlight>
	~~</syntaxhighlight>~~		clean_onto(onto)
			_empty_graph = onto2graph(onto)

	~~To print an ontology without standard triples~~, ~~you must first run this code at the beginning of the program:~~		def print_onto(onto):
	~~<syntaxhighlight>~~		g = onto2graph(onto)
			for t in _empty_graph:
			if t in g:
			g.remove(t)
			g.bind('', Namespace(BASE))
			print(g.serialize(format='ttl'))
	</syntaxhighlight>		</syntaxhighlight>

Line 85:		Line 109:

	==Useful readings==		==Useful readings==
	* [https://~~www.w3~~.org/TR/~~owl-primer~~/ ~~OWL2 Primer~~]		* [https://pypi.org/project/Owlready2/ Project description] and ''What can I do with Owlready2?''
	* [https://~~www~~.w3.~~org/TR~~/~~2012~~/~~REC-owl2-quick-reference-20121211~~/ ~~OWL2 Quick Reference Guide~~]		* [https://owlready2.readthedocs.io/en/latest/ Welcome to Owlready2's Documentation]

Sinoa: Created page with " =Lab 12: Even more OWL= ==Topics== OWL ontology programming with owlready2. ==Classes and methods== In an earlier lab, you have already used these O..."

2022-04-14T11:22:32Z

Created page with " =Lab 12: Even more OWL= ==Topics== OWL ontology programming with owlready2.  ==Classes and methods== In an earlier lab, you have already used these O..."

New page

=Lab 12: Even more OWL=

==Topics==
OWL ontology programming with owlready2.



==Classes and methods==
In an earlier lab, you have already used these OWL concepts:
* (sameAs, equivalentClass, equivalentProperty, differentFrom, disjointWith, inverseOf)
* (ReflexiveProperty, IrreflexiveProperty, SymmetricProperty, AsymmetricProperty, TransitiveProperty, FunctionalProperty, InverseFunctionalProperty),
* (oneOf, unionOf, intersectionOf. complementOf)
* (Restriction, onProperty)
* (someValuesFrom, allValuesFrom, hasValue)
* (cardinality, minCardinality, maxCardinality)
* (qualifiedCardinality, minQualifiedCardinality, maxQualifiedCardinality, onClass)

==Owlready2==
This lab will re-write the same OWL expressions as in an earlier lab, but using owlready2 instead of rdflib.

The [https://pypi.org/project/Owlready2/ Project description] and section ''What can I do with Owlready2?'' gives a brief introduction to installing and getting started with owlready2. You will find more documentation at [https://owlready2.readthedocs.io/en/latest/ Welcome to Owlready2's Documentation]

For example:
<syntaxhighlight>
# A graduate is a student with at least one degree.
with onto:
class Student(Thing): pass
class Degree(Thing): pass
class hasDegree(Student >> Degree): pass
class Graduate(Student):
is_a = [hasDegree.some(Degree)]
</syntaxhighlight>

==Tasks==
Re-write the same OWL expressions as in an earlier lab, but using owlready2 instead of rdflib:
* anyone who is a graduate has at least one degree
* anyone who is a university graduate has at least one degree from a university
* a grade is either an A, B, C, D, E or F
* a straight A student is a student that has only A grades
* a graduate has no F grades
* a student has a unique student number
* each student has exactly one average grade
* a course is either a bachelor, a master or a Ph.D course
* a bachelor student takes only bachelor courses
* a master student takes only master courses, except for at most one bachelor course
* a Ph.D student takes only Ph.D courses, except for at most two masters courses
* a Ph.D. student cannot take any bachelor course

==Code to get started==
(These need more testing!)

Empty an ontology (otherwise owlready2 remembers ontologies between sessions!):
<syntaxhighlight>
</syntaxhighlight>

Print an ontology:
<syntaxhighlight>
</syntaxhighlight>

Print an ontology without standard triples:
<syntaxhighlight>
</syntaxhighlight>

To print an ontology without standard triples, you must first run this code at the beginning of the program:
<syntaxhighlight>
</syntaxhighlight>

==If You Have More Time==
Populate the ontology with individals, such as:
<syntaxhighlight>
with onto:
cade = Student()
infosci = Degree()
cade.hasDegree.append(infosci)
</syntaxhighlight>

Try to use Hermit as in the lecture to infer additional triples.
IMPORANT: Neither Hermit/Pellet nor OWL-RL are able to reason with the full OWL-DL. But unlike OWL-RL, Owlready2 supports reaosning over many types of restrictions.

==Useful readings==
* [https://www.w3.org/TR/owl-primer/ OWL2 Primer]
* [https://www.w3.org/TR/2012/REC-owl2-quick-reference-20121211/ OWL2 Quick Reference Guide]