Support Python 3

We had tried to support Python 3 previously, but we were not testing
under Python 3 to ensure that we maintained that support.

This change adds testing for Python 3 and fixes the breakages that have
crept in since our previous effort

This also fixes a transient error in the bigquery tests where
the test only passed if they completed in less than 1 microsecond.

.travis.yml

@@ -1,6 +1,7 @@
 language: python
 python:
   - "2.7"
+  - "3.4"
 
 before_install:
   - npm install -g typescript

datalab/utils/_http.py

@@ -132,7 +132,10 @@ def request(url, args=None, data=None, headers=None, method=None,
       if 200 <= response.status < 300:
         if raw_response:
           return content
-        return json.loads(str(content, encoding='UTF-8'))
+        if type(content) == str:
+          return json.loads(content)
+        else:
+          return json.loads(str(content, encoding='UTF-8'))
       else:
         raise RequestException(response.status, content)
     except ValueError:

datalab/utils/_utils.py

@@ -16,7 +16,11 @@
 from __future__ import unicode_literals
 from builtins import str
 
-import httplib
+try:
+    import http.client as httplib
+except ImportError:
+    import httplib
+
 import pytz
 import socket
 import traceback

tests/bigquery/table_tests.py

@@ -101,7 +101,7 @@ def test_table_metadata(self, mock_api_tables_get):
     self.assertEqual('Logs', metadata.friendly_name)
     self.assertEqual(2, metadata.rows)
     self.assertEqual(2, metadata.rows)
-    self.assertEqual(ts, metadata.created_on)
+    self.assertTrue(abs((metadata.created_on - ts).total_seconds()) <= 1)
     self.assertEqual(None, metadata.expires_on)
 
   @mock.patch('datalab.bigquery._api.Api.tables_get')

tests/main.py

@@ -91,4 +91,4 @@
   runner = unittest.TextTestRunner()
   result = runner.run(suite)
 
-  sys.exit(len(result.errors))
+  sys.exit(len(result.errors) + len(result.failures))

tests/stackdriver/monitoring/metric_tests.py

@@ -137,7 +137,7 @@ def test_as_dataframe(self, mock_datalab_list_descriptors):
     self.assertEqual(dataframe.columns.tolist(), expected_headers)
     self.assertEqual(dataframe.columns.names, [None])
 
-    self.assertEqual(dataframe.index.tolist(), range(len(METRIC_TYPES)))
+    self.assertEqual(dataframe.index.tolist(), list(range(len(METRIC_TYPES))))
     self.assertEqual(dataframe.index.names, [None])
 
     expected_labels = 'instance_name, device_name'

tests/stackdriver/monitoring/resource_tests.py

@@ -123,7 +123,7 @@ def test_as_dataframe(self, mock_datalab_list_descriptors):
     self.assertEqual(dataframe.columns.tolist(), expected_headers)
     self.assertEqual(dataframe.columns.names, [None])
 
-    self.assertEqual(dataframe.index.tolist(), range(len(RESOURCE_TYPES)))
+    self.assertEqual(dataframe.index.tolist(), list(range(len(RESOURCE_TYPES))))
     self.assertEqual(dataframe.index.names, [None])
 
     expected_labels = 'instance_id, project_id'