René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"There is no Query.ancestor accessor.","articleBody":"For example if a query is passes `q.ancestor(None)` the [returned](https://github.com/GoogleCloudPlatform/gcloud-python/blob/c2ba130223d23c661e0844145a90c8f451de297d/gcloud/datastore/query.py#L208) object is a clone with the ancestor removed (i.e. literally set the ancestor to `None`). This behavior is not mentioned in the docstring and should be added.\n\nIn order to actually access the `ancestor`, a user needs to parse it from the query's protobuf:\n\n``` python\n\u003e\u003e\u003e from gcloud import datastore\n\u003e\u003e\u003e from gcloud.datastore import datastore_v1_pb2 as datastore_pb\n\u003e\u003e\u003e ANCESTOR = {'kind': 'Book', 'name': 'GoT'}\n\u003e\u003e\u003e ANCESTOR_KEY = datastore.key.Key(path=[ANCESTOR])\n\u003e\u003e\u003e dataset = datastore.dataset.Dataset('foo')\n\u003e\u003e\u003e q = dataset.query('Character').ancestor(ANCESTOR_KEY)\n\u003e\u003e\u003e ancestor_filters = {\n...     i: filter_obj\n...     for i, filter_obj in enumerate(q._pb.filter.composite_filter.filter)\n...     if (filter_obj.property_filter.operator ==\n...         datastore_pb.PropertyFilter.HAS_ANCESTOR)\n... }\n\u003e\u003e\u003e # for key in ancestor_filters.keys():\n... #     del q._pb.filter.composite_filter.filter[key]\n... # # If q has no more filters...\n... # if not q._pb.filter.composite_filter.filter:\n... #     q._pb.ClearField('filter')\n... _, filter_obj = ancestor_filters.popitem()\n\u003e\u003e\u003e ancestor_filter = filter_obj.property_filter\n\u003e\u003e\u003e ancestor_filter.property.name\nu'__key__'\n\u003e\u003e\u003e ancestor_filter.operator == datastore_pb.PropertyFilter.HAS_ANCESTOR\nTrue\n\u003e\u003e\u003e key_pb = ancestor_filter.value.key_value\n\u003e\u003e\u003e key_pb\n\u003cgcloud.datastore.datastore_v1_pb2.Key object at 0x7f069f2372a8\u003e\n\u003e\u003e\u003e key = datastore.helpers.key_from_protobuf(key_pb)\n\u003e\u003e\u003e key\n\u003cKey[{'kind': u'Book', 'name': u'GoT'}]\u003e\n\u003e\u003e\u003e ANCESTOR_KEY\n\u003cKey[{'kind': 'Book', 'name': 'GoT'}]\u003e\n```\n","author":{"url":"https://github.com/dhermes","@type":"Person","name":"dhermes"},"datePublished":"2014-12-17T23:17:36.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/431/google-cloud-python/issues/431"}