getting actual concepts value instead of its URI in ontology

Question

I am using owl ontology for semantic analysis in emotional sentiment analysis project , I am trying to navigate the ontology to check a concepts and its relation , my ontology has classes like this :

<!-- http://purl.obolibrary.org/obo/MFOEM_000011 -->

<owl:Class rdf:about="http://purl.obolibrary.org/obo/MFOEM_000011">
    <rdfs:subClassOf rdf:resource="http://purl.obolibrary.org/obo/MFOEM_000001" />
    <rdfs:subClassOf>
        <owl:Restriction>
            <owl:onProperty rdf:resource="http://purl.obolibrary.org/obo/BFO_0000117" />
            <owl:someValuesFrom rdf:resource="http://purl.obolibrary.org/obo/MFOEM_000208" />
        </owl:Restriction>
    </rdfs:subClassOf>
    <obo:IAO_0000115>An unpleasant emotion closely related to anger but lower in intensity and without the moral dimension of blame and seriousness that is implicated in anger. [Source: OCEAS]</obo:IAO_0000115>
    <obo:MFOEM_000010 xml:lang="es">irritación</obo:MFOEM_000010>
    <obo:MFOEM_000010 xml:lang="fr">irritation</obo:MFOEM_000010>
    <obo:MFOEM_000010 xml:lang="de">Ärger</obo:MFOEM_000010>
    <obo:MFOEM_000165>irritated</obo:MFOEM_000165>
    <rdfs:label>irritation</rdfs:label>
</owl:Class>

I am using this code to retrieve concepts from triples s,p,o :

from rdflib.namespace import RDF, RDFS, OWL ,FOAF
from pprint import pprint


properties2=set()
for p in g.subjects():
    properties2.add(p)    
pprint(properties2)

and the output is something like this :

 rdflib.term.URIRef('http://purl.obolibrary.org/obo/MFOEM_000221')
 rdflib.term.URIRef('http://purl.obolibrary.org/obo/MFOEM_000222')
 rdflib.term.URIRef('http://purl.obolibrary.org/obo/MFOEM_000223')
 rdflib.term.URIRef('http://purl.obolibrary.org/obo/MF_0000020')
 rdflib.term.URIRef('http://purl.obolibrary.org/obo/MF_0000029')
 rdflib.term.URIRef('http://purl.obolibrary.org/obo/MF_0000031')
 rdflib.term.URIRef('http://purl.obolibrary.org/obo/MF_0000039')
 rdflib.term.URIRef('http://purl.obolibrary.org/obo/NBO_0000003')
 rdflib.term.URIRef('http://purl.obolibrary.org/obo/comment')
 rdflib.term.URIRef('http://purl.org/dc/elements/1.1/contributor')
 rdflib.term.URIRef('http://purl.org/dc/elements/1.1/title')
 rdflib.term.URIRef('http://www.w3.org/2000/01/rdf-schema#comment')
 rdflib.term.URIRef('http://www.w3.org/2000/01/rdf-schema#label')}

but ,it return URIRef instead of the concept value can anyone help me to understand why it returns that and how can I get the actual concepts behind of URI excuse me if I have misunderstanding but , I am new in this topic and i did a hard googling and didn't find any reslut