Add Snippet for Listing All Subscriptions in a Project [(#1169)](GoogleCloudPlatform/python-docs-samples#1169)

Author: michaelawyu

samples/snippets/subscriber.py

@@ -27,7 +27,7 @@
 from google.cloud import pubsub_v1
 
 
-def list_subscriptions(project, topic_name):
+def list_subscriptions_in_topic(project, topic_name):
     """Lists all subscriptions for a given topic."""
     subscriber = pubsub_v1.SubscriberClient()
     topic_path = subscriber.topic_path(project, topic_name)
@@ -36,6 +36,15 @@ def list_subscriptions(project, topic_name):
         print(subscription.name)
 
 
+def list_subscriptions_in_project(project):
+    """Lists all subscriptions in the current project."""
+    subscriber = pubsub_v1.SubscriberClient()
+    project_path = subscriber.project_path(project)
+
+    for subscription in subscriber.list_subscriptions(project_path):
+        print(subscription.name)
+
+
 def create_subscription(project, topic_name, subscription_name):
     """Create a new pull subscription on the given topic."""
     subscriber = pubsub_v1.SubscriberClient()
@@ -109,9 +118,12 @@ def callback(message):
     parser.add_argument('project', help='Your Google Cloud project ID')
 
     subparsers = parser.add_subparsers(dest='command')
-    list_parser = subparsers.add_parser(
-        'list', help=list_subscriptions.__doc__)
-    list_parser.add_argument('topic_name')
+    list_in_topic_parser = subparsers.add_parser(
+        'list_in_topic', help=list_subscriptions_in_topic.__doc__)
+    list_in_topic_parser.add_argument('topic_name')
+
+    list_in_project_parser = subparsers.add_parser(
+        'list_in_project', help=list_subscriptions_in_project.__doc__)
 
     create_parser = subparsers.add_parser(
         'create', help=create_subscription.__doc__)
@@ -133,8 +145,10 @@ def callback(message):
 
     args = parser.parse_args()
 
-    if args.command == 'list':
-        list_subscriptions(args.project, args.topic_name)
+    if args.command == 'list_in_topic':
+        list_subscriptions_in_topic(args.project, args.topic_name)
+    elif args.command == 'list_in_project':
+        list_subscriptions_in_project(args.project)
     elif args.command == 'create':
         create_subscription(
             args.project, args.topic_name, args.subscription_name)

samples/snippets/subscriber_test.py

@@ -66,10 +66,18 @@ def subscription(subscriber_client, topic):
     yield subscription_path
 
 
-def test_list(subscription, capsys):
+def test_list_in_topic(subscription, capsys):
     @eventually_consistent.call
     def _():
-        subscriber.list_subscriptions(PROJECT, TOPIC)
+        subscriber.list_subscriptions_in_topic(PROJECT, TOPIC)
+        out, _ = capsys.readouterr()
+        assert subscription in out
+
+
+def test_list_in_project(subscription, capsys):
+    @eventually_consistent.call
+    def _():
+        subscriber.list_subscriptions_in_project(PROJECT)
         out, _ = capsys.readouterr()
         assert subscription in out