René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"GAX iter.next() pattern seems to be breaking down","articleBody":"[For example](https://travis-ci.org/GoogleCloudPlatform/gcloud-python/builds/153445840), sometimes the iterable isn't an iterable\n\n``` python\nTraceback (most recent call last):\n  File \"/home/travis/build/GoogleCloudPlatform/gcloud-python/system_tests/logging_.py\", line 215, in test_update_metric\n    after_metrics, _ = Config.CLIENT.list_metrics()\n  File \"/home/travis/build/GoogleCloudPlatform/gcloud-python/.tox/system-tests3/lib/python3.4/site-packages/gcloud/logging/client.py\", line 298, in list_metrics\n    self.project, page_size, page_token)\n  File \"/home/travis/build/GoogleCloudPlatform/gcloud-python/.tox/system-tests3/lib/python3.4/site-packages/gcloud/logging/_gax.py\", line 306, in list_metrics\n    for log_metric_pb in page_iter.next()]\nTypeError: 'LogMetric' object is not iterable\n```\n\nor\n\n``` python\nTraceback (most recent call last):\n  File \"/home/travis/build/GoogleCloudPlatform/gcloud-python/system_tests/pubsub.py\", line 273, in test_fetch_delete_subscription_w_deleted_topic\n    all_subs = retry_until_found_orphan(_fetch)()\n  File \"/home/travis/build/GoogleCloudPlatform/gcloud-python/system_tests/retry.py\", line 126, in wrapped_function\n    result = to_wrap(*args, **kwargs)\n  File \"/home/travis/build/GoogleCloudPlatform/gcloud-python/system_tests/pubsub.py\", line 266, in _fetch\n    return list(MethodIterator(Config.CLIENT.list_subscriptions))\n  File \"/home/travis/build/GoogleCloudPlatform/gcloud-python/.tox/system-tests/lib/python2.7/site-packages/gcloud/iterator.py\", line 178, in __iter__\n    page_token=self._token, page_size=self._page_size, **self._kw)\n  File \"/home/travis/build/GoogleCloudPlatform/gcloud-python/.tox/system-tests/lib/python2.7/site-packages/gcloud/pubsub/client.py\", line 164, in list_subscriptions\n    self.project, page_size, page_token)\n  File \"/home/travis/build/GoogleCloudPlatform/gcloud-python/.tox/system-tests/lib/python2.7/site-packages/gcloud/pubsub/_gax.py\", line 242, in list_subscriptions\n    for sub_pb in page_iter.next()]\nTypeError: 'Subscription' object is not iterable\n```\n\nand sometimes it just gives a `StopIteration` when a new page is expected\n\n``` python\nTraceback (most recent call last):\n  File \"/home/travis/build/GoogleCloudPlatform/gcloud-python/system_tests/pubsub.py\", line 130, in test_list_subscriptions\n    empty, _ = topic.list_subscriptions()\n  File \"/home/travis/build/GoogleCloudPlatform/gcloud-python/.tox/system-tests/lib/python2.7/site-packages/gcloud/pubsub/topic.py\", line 314, in list_subscriptions\n    self.full_name, page_size, page_token)\n  File \"/home/travis/build/GoogleCloudPlatform/gcloud-python/.tox/system-tests/lib/python2.7/site-packages/gcloud/pubsub/_gax.py\", line 198, in topic_list_subscriptions\n    subs = page_iter.next()\n  File \"/home/travis/build/GoogleCloudPlatform/gcloud-python/.tox/system-tests/lib/python2.7/site-packages/google/gax/__init__.py\", line 472, in next\n    return self.__next__()\n  File \"/home/travis/build/GoogleCloudPlatform/gcloud-python/.tox/system-tests/lib/python2.7/site-packages/google/gax/__init__.py\", line 478, in __next__\n    self._current = next(self._page_iterator)\n  File \"/home/travis/build/GoogleCloudPlatform/gcloud-python/.tox/system-tests/lib/python2.7/site-packages/google/gax/__init__.py\", line 435, in next\n    return self.__next__()\n  File \"/home/travis/build/GoogleCloudPlatform/gcloud-python/.tox/system-tests/lib/python2.7/site-packages/google/gax/__init__.py\", line 440, in __next__\n    raise StopIteration\nStopIteration\n```\n\nI withhold the `flaky` label because the same 10 test cases fail every time and in both Python 2 and 3:\n1. `test_fetch_delete_subscription_w_deleted_topic (pubsub.TestPubsub)`\n2. `test_list_subscriptions (pubsub.TestPubsub)`\n3. `test_list_topics (pubsub.TestPubsub)`\n4. `test_list_metrics (logging_.TestLogging)`\n5. `test_list_sinks (logging_.TestLogging)`\n6. `test_log_struct (logging_.TestLogging)`\n7. `test_log_struct_w_metadata (logging_.TestLogging)`\n8. `test_log_text (logging_.TestLogging)`\n9. `test_log_text_w_metadata (logging_.TestLogging)`\n10. `test_update_metric (logging_.TestLogging)`\n","author":{"url":"https://github.com/dhermes","@type":"Person","name":"dhermes"},"datePublished":"2016-08-19T04:56:54.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":5},"url":"https://github.com/2140/google-cloud-python/issues/2140"}