Modify get_task_value to match comment. (#447)

Author: colincadams

opencensus/stats/exporters/stackdriver_exporter.py

@@ -421,10 +421,10 @@ def get_task_value():
     """ getTaskValue returns a task label value in the format of
      "py-<pid>@<hostname>".
     """
-    task_value = "py@" + str(os.getpid())
     hostname = platform.uname()[1]
-    task_value += hostname if hostname is not None else "localhost"
-    return task_value
+    if not hostname:
+        hostname = "localhost"
+    return "py-%s@%s" % (os.getpid(), hostname)
 
 
 def namespaced_view_name(view_name, metric_prefix):

tests/unit/stats/exporter/test_stackdriver_stats.py

@@ -291,7 +291,7 @@ def assertCorrectLabels(self, actual_labels, expected_labels,
         if include_opencensus:
             opencensus_tag = actual_labels.pop(stackdriver.OPENCENSUS_TASK)
             self.assertIsNotNone(opencensus_tag)
-            self.assertIn("py@", opencensus_tag)
+            self.assertIn("py-", opencensus_tag)
         self.assertDictEqual(actual_labels, expected_labels)
 
     @mock.patch('opencensus.stats.exporters.stackdriver_exporter.'
@@ -1093,11 +1093,11 @@ def test_set_metric_labels_with_None(self):
                                                 'version', 'machine',
                                                 'processor'))
     def test_get_task_value_with_hostname(self, mock_uname, mock_pid):
-        self.assertEqual(stackdriver.get_task_value(), "py@12345node")
+        self.assertEqual(stackdriver.get_task_value(), "py-12345@node")
 
     @mock.patch('os.getpid', return_value=12345)
-    @mock.patch('platform.uname', return_value=('system', None, 'release',
+    @mock.patch('platform.uname', return_value=('system', '', 'release',
                                                 'version', 'machine',
                                                 'processor'))
     def test_get_task_value_without_hostname(self, mock_uname, mock_pid):
-        self.assertEqual(stackdriver.get_task_value(), "py@12345localhost")
+        self.assertEqual(stackdriver.get_task_value(), "py-12345@localhost")