Add autocompletion for namespaces (IPython only) (#599)

* Add autocompletion for namespaces.

* Unit tests for IPython autocompletion.

osp/core/ontology/namespace.py

@@ -4,7 +4,7 @@
 from collections.abc import Iterable
 import rdflib
 import logging
-
+import itertools
 from osp.core.ontology.entity import OntologyEntity
 from osp.core.ontology.relationship import OntologyRelationship
 from osp.core.ontology.cuba import rdflib_cuba
@@ -32,6 +32,17 @@ def __init__(self, name, namespace_registry, iri):
         self._reference_by_label = \
             namespace_registry._get_reference_by_label(self._iri)
 
+    def __dir__(self):
+        """Attributes available for the OntologyNamespace class.
+
+        Returns:
+            Iterable: the available attributes, which include the methods and
+                      the ontology entities in the namespace.
+        """
+        entity_autocompletion = self._iter_labels() \
+            if self._reference_by_label else self._iter_suffixes()
+        return itertools.chain(dir(super()), entity_autocompletion)
+
     def __str__(self):
         """Transform the namespace to a human readable string.
 
@@ -254,20 +265,46 @@ def _get_from_label(self, label, lang=None, case_sensitive=False):
             results[0] = results[0].inverse
         return results[0]
 
-    def __iter__(self):
-        """Iterate over the ontology entities in the namespace.
+    def _iter_iris(self):
+        """Iterate over the IRIs of the ontology entities in the namespace.
 
-        :return: An iterator over the entities.
-        :rtype: Iterator[OntologyEntity]
+        :return: An iterator over the entity IRIs.
+        :rtype: Iterator[rdflib.URIRef]
         """
         types = [rdflib.OWL.DatatypeProperty,
                  rdflib.OWL.ObjectProperty,
                  rdflib.OWL.Class]
-        return (self._namespace_registry.from_iri(s)
+        return (s
                 for t in types
                 for s, _, _ in self._graph.triples((None, rdflib.RDF.type, t))
                 if s in self)
 
+    def __iter__(self):
+        """Iterate over the ontology entities in the namespace.
+
+        :return: An iterator over the entities.
+        :rtype: Iterator[OntologyEntity]
+        """
+        return (self._namespace_registry.from_iri(iri)
+                for iri in self._iter_iris())
+
+    def _iter_labels(self):
+        """Iterate over the labels of the ontology entities in the namespace.
+
+        :return: An iterator over the entity labels.
+        :rtype: Iterator[str]
+        """
+        return itertools.chain(*(self._get_labels_for_iri(iri)
+                                 for iri in self._iter_iris()))
+
+    def _iter_suffixes(self):
+        """Iterate over suffixes of the ontology entities in the namespace.
+
+        :return: An iterator over the entity suffixes.
+        :rtype: Iterator[str]
+        """
+        return (str(iri)[len(str(self._iri)):] for iri in self._iter_iris())
+
     def __contains__(self, item):
         """Check whether the given entity is part of the namespace.
 

tests/test_namespace.py

@@ -515,6 +515,16 @@ def test_get_entity_name(self):
             "City_T"
         )
 
+    def test_autocompletion_ipython(self):
+        """Checks that all the expected ontology entities are in __dir__.
+
+        The check is done just for the `cuba` namespace.
+        """
+        expected = {'activeRelationship', 'passiveRelationship',
+                    'relationship', 'attribute', 'path', 'Entity', 'File',
+                    'Nothing', 'Wrapper'}
+        self.assertSetEqual(set(dir(cuba)) & expected, expected)
+
 
 if __name__ == "__main__":
     unittest.main()