Adapt TemplatizableDict to python3 hasattr

In python 3, hasattr() expects __getattr__ to raise an AttributeError if
the attribute does not exist. This updates TemplatizableDict accordingly.

Change-Id: I989b5c5d8888bce47fa8c8d7157097d3ea48e0b5

cloudkittydashboard/tests/test_utils.py

@@ -0,0 +1,28 @@
+# Copyright 2019 Objectif Libre
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+import unittest
+
+from cloudkittydashboard import utils
+
+
+class TemplatizableDictTest(unittest.TestCase):
+
+    def test_hasattr_attr_exists(self):
+        obj = utils.TemplatizableDict(a=1, b=2)
+        self.assertTrue(hasattr(obj, 'a'))
+
+    def test_hasattr_attr_does_not_exist(self):
+        obj = utils.TemplatizableDict(a=1, b=2)
+        self.assertFalse(hasattr(obj, 'c'))

cloudkittydashboard/utils.py

@@ -19,7 +19,9 @@ class TemplatizableDict(dict):
     """Class allowing to pass a dict to horizon templates"""
 
     def __getattr__(self, key):
-        return self[key]
+        if key in self.keys():
+            return self[key]
+        raise AttributeError("Object has no {} attribute".format(key))
 
     def __setattr__(self, key, val):
         self[key] = val