Merge pull request #866 from joernhees/enh827

ClosedNamespace returns right exception for way of access, enhances #827

Author: joernhees

rdflib/namespace.py

@@ -169,7 +169,7 @@ def __init__(self, uri, terms):
     def term(self, name):
         uri = self.__uris.get(name)
         if uri is None:
-            raise AttributeError(
+            raise KeyError(
                 "term '{}' not in namespace '{}'".format(name, self.uri)
             )
         else:
@@ -182,7 +182,10 @@ def __getattr__(self, name):
         if name.startswith("__"):  # ignore any special Python names!
             raise AttributeError
         else:
-            return self.term(name)
+            try:
+                return self.term(name)
+            except KeyError as e:
+                raise AttributeError(e)
 
     def __str__(self):
         return text_type(self.uri)