unit test fix - if libraries can not be imported

Author: mhaseebtariq

pandas/io/gbq.py

@@ -168,13 +168,25 @@ def get_credentials(self):
 
     @staticmethod
     def get_application_default_credentials(project_id):
-        from oauth2client.client import GoogleCredentials
-        from oauth2client.client import AccessTokenRefreshError
-        from oauth2client.client import ApplicationDefaultCredentialsError
-        from apiclient.discovery import build
-        from apiclient.errors import HttpError
-
+        """
+        Given a project_id tries to retrieve the 
+        "default application credentials"
+        Could be useful for running code on Google Cloud Platform
+        """
         credentials = None
+        try:
+            from oauth2client.client import GoogleCredentials
+            from oauth2client.client import AccessTokenRefreshError
+            from oauth2client.client import ApplicationDefaultCredentialsError
+            try:
+                from googleapiclient.discovery import build
+                from googleapiclient.errors import HttpError
+            except:
+                from apiclient.discovery import build
+                from apiclient.errors import HttpError
+        except ImportError:
+            return None
+
         try:
             credentials = GoogleCredentials.get_application_default()
         except ApplicationDefaultCredentialsError:

pandas/io/tests/test_gbq.py

@@ -83,7 +83,8 @@ def _test_imports():
             from oauth2client.client import GoogleCredentials  # noqa
             from oauth2client.client import OAuth2WebServerFlow  # noqa
             from oauth2client.client import AccessTokenRefreshError  # noqa
-            from oauth2client.client import ApplicationDefaultCredentialsError  # noqa
+            from oauth2client.client import \
+            ApplicationDefaultCredentialsError  # noqa
 
             from oauth2client.file import Storage  # noqa
             from oauth2client.tools import run_flow  # noqa
@@ -137,7 +138,8 @@ def _test_imports():
         oauth2client_v1 = False
 
     try:
-        from oauth2client.service_account import ServiceAccountCredentials  # noqa
+        from oauth2client.service_account import \
+        ServiceAccountCredentials  # noqa
     except ImportError:
         oauth2client_v2 = False
 
@@ -159,7 +161,8 @@ def clean_gbq_environment(private_key=None):
     for i in range(1, 10):
         if DATASET_ID + str(i) in dataset.datasets():
             dataset_id = DATASET_ID + str(i)
-            table = gbq._Table(PROJECT_ID, dataset_id, private_key=private_key)
+            table = gbq._Table(PROJECT_ID, dataset_id, 
+                               private_key=private_key)
             for j in range(1, 20):
                 if TABLE_ID + str(j) in dataset.tables(dataset_id):
                     table.delete(TABLE_ID + str(j))