Note that key_filter is a helper for add_filter('__key__'). (GoogleCloudPlatform#1937)

sorced-jim · engelke · commit 2094cb448b68 · 2019-01-25T14:50:38.000-08:00
diff --git a/datastore/cloud-client/snippets.py b/datastore/cloud-client/snippets.py
@@ -409,6 +409,7 @@ def key_filter(client):
     # [START datastore_key_filter]
     query = client.query(kind='Task')
     first_key = client.key('Task', 'first_task')
+    # key_filter(key, op) translates to add_filter('__key__', op, key).
     query.key_filter(first_key, '>')
     # [END datastore_key_filter]
 
