Expose 'exclude_from_indexes' via 'Dataset.entity()'.

Incorporates feedback from @dhermes.

Author: tseaver

gcloud/datastore/dataset.py

@@ -78,16 +78,21 @@ def query(self, *args, **kwargs):
         kwargs['dataset'] = self
         return Query(*args, **kwargs)
 
-    def entity(self, kind):
+    def entity(self, kind, exclude_from_indexes=()):
         """Create an entity bound to this dataset.
 
         :type kind: string
         :param kind: the "kind" of the new entity.
 
+        :type exclude_from_indexes: sequence of str
+        :param exclude_from_indexes: Names of properties *not* to be indexed
+                                     for the entity.
+
         :rtype: :class:`gcloud.datastore.entity.Entity`
         :returns: a new Entity instance, bound to this dataset.
         """
-        return Entity(dataset=self, kind=kind)
+        return Entity(dataset=self, kind=kind,
+                      exclude_from_indexes=exclude_from_indexes)
 
     def transaction(self, *args, **kwargs):
         """Create a transaction bound to this dataset.

gcloud/datastore/test_dataset.py

@@ -34,14 +34,25 @@ def test_query_factory(self):
         self.assertIsInstance(query, Query)
         self.assertTrue(query.dataset() is dataset)
 
-    def test_entity_factory(self):
+    def test_entity_factory_defaults(self):
         from gcloud.datastore.entity import Entity
         DATASET_ID = 'DATASET'
         KIND = 'KIND'
         dataset = self._makeOne(DATASET_ID)
         entity = dataset.entity(KIND)
         self.assertIsInstance(entity, Entity)
         self.assertEqual(entity.kind(), KIND)
+        self.assertEqual(sorted(entity.exclude_from_indexes()), [])
+
+    def test_entity_factory_explicit(self):
+        from gcloud.datastore.entity import Entity
+        DATASET_ID = 'DATASET'
+        KIND = 'KIND'
+        dataset = self._makeOne(DATASET_ID)
+        entity = dataset.entity(KIND, ['foo', 'bar'])
+        self.assertIsInstance(entity, Entity)
+        self.assertEqual(entity.kind(), KIND)
+        self.assertEqual(sorted(entity.exclude_from_indexes()), ['bar', 'foo'])
 
     def test_transaction_factory(self):
         from gcloud.datastore.transaction import Transaction