Adding Namespace.__contains__()

rdflib/namespace.py

@@ -112,7 +112,11 @@ class Namespace(str):
     rdflib.term.URIRef(u'http://example.org/Person')
     >>> n['first-name'] # as item - for things that are not valid python identifiers
     rdflib.term.URIRef(u'http://example.org/first-name')
-
+    >>> n.Person in n
+    True
+    >>> n2 = Namespace("http://example2.org/")
+    >>> n.Person in n2
+    False
     """
 
     def __new__(cls, value):
@@ -141,6 +145,9 @@ def __getattr__(self, name):
 
     def __repr__(self):
         return "Namespace(%r)" % str(self)
+
+    def __contains__(self, ref):
+        return ref.startswith(self) # test namespace membership with "ref in ns" syntax
 
 
 class URIPattern(str):
@@ -187,11 +194,10 @@ def __init__(self, uri, terms):
             self.__uris[t] = URIRef(self.uri + t)
 
     def term(self, name):
-        uri = self.__uris.get(name)
-        if uri is None:
+        if name not in self.__uris:
             raise KeyError("term '{}' not in namespace '{}'".format(name, self.uri))
         else:
-            return uri
+            return self.__uris[name]
 
     def __getitem__(self, key, default=None):
         return self.term(key)
@@ -213,9 +219,12 @@ def __repr__(self):
 
     def __dir__(self):
         return list(self._ClosedNamespace__uris)
+
+    def __contains__(self, ref):
+        return ref in self.__uris.values() # test namespace membership with "ref in ns" syntax
 
     def _ipython_key_completions_(self):
-        return dir(self)
+        return dir(self.uri)
 
 
 class _RDFNamespace(ClosedNamespace):
@@ -590,6 +599,13 @@ def __init__(self, graph):
         self.bind("rdfs", RDFS)
         self.bind("xsd", XSD)
 
+    def __contians__(self, ref):
+        # checks if a reference is in any of the managed namespaces with syntax
+        # "ref in manager". Note that we don't use "ref in ns", as 
+        # NamespaceManager.namespaces() returns Iterator[Tuple[str, URIRef]]
+        # rather than Iterator[Tuple[str, Namespace]]
+        return any(ref.startswith(ns) for prefix, ns in self.namespaces())
+
     def reset(self):
         self.__cache = {}
         self.__strie = {}

test/test_namespace.py

@@ -1,7 +1,7 @@
 import unittest
 
 from rdflib.graph import Graph
-from rdflib.namespace import FOAF
+from rdflib.namespace import Namespace, FOAF, RDF, RDFS, SH
 from rdflib.term import URIRef
 
 
@@ -112,3 +112,18 @@ def add_not_in_namespace(s):
             add_not_in_namespace("givenName"),
             URIRef("http://xmlns.com/foaf/0.1/givenName"),
         )
+
+    def test_contains_method(self):
+        """Tests for Namespace.__contains__() methods."""
+
+        ref = URIRef('http://www.w3.org/ns/shacl#example')
+        self.assertTrue(type(SH) == Namespace, "SH no longer a Namespace, update test.")
+        self.assertTrue(ref in SH, "sh:example not in SH")
+
+        ref = URIRef('http://www.w3.org/2000/01/rdf-schema#label')
+        self.assertTrue(ref in RDFS, "ClosedNamespace(RDFS) does not include rdfs:label")
+        ref = URIRef('http://www.w3.org/2000/01/rdf-schema#example')
+        self.assertFalse(ref in RDFS, "ClosedNamespace(RDFS) includes out-of-ns member rdfs:example")
+
+        ref = URIRef('http://www.w3.org/1999/02/22-rdf-syntax-ns#type')
+        self.assertTrue(ref in RDF, "_RDFNamespace does not include rdf:type")