Pub/Sub: moved import statements inside region tags [(#1753)](GoogleC…

…loudPlatform/python-docs-samples#1753)

* Moved import stataments inside region tags

* Explained topic and subscription path methods

samples/snippets/publisher.py

@@ -22,70 +22,95 @@
 """
 
 import argparse
-import time
 
-from google.cloud import pubsub_v1
 
-
-def list_topics(project):
+def list_topics(project_id):
     """Lists all Pub/Sub topics in the given project."""
     # [START pubsub_list_topics]
+    from google.cloud import pubsub_v1
+
+    # TODO project_id = "Your Google Cloud Project ID"
+
     publisher = pubsub_v1.PublisherClient()
-    project_path = publisher.project_path(project)
+    project_path = publisher.project_path(project_id)
 
     for topic in publisher.list_topics(project_path):
         print(topic)
     # [END pubsub_list_topics]
 
 
-def create_topic(project, topic_name):
+def create_topic(project_id, topic_name):
     """Create a new Pub/Sub topic."""
     # [START pubsub_create_topic]
+    from google.cloud import pubsub_v1
+
+    # TODO project_id = "Your Google Cloud Project ID"
+    # TODO topic_name = "Your Pub/Sub topic name"
+
     publisher = pubsub_v1.PublisherClient()
-    topic_path = publisher.topic_path(project, topic_name)
+    topic_path = publisher.topic_path(project_id, topic_name)
 
     topic = publisher.create_topic(topic_path)
 
     print('Topic created: {}'.format(topic))
     # [END pubsub_create_topic]
 
 
-def delete_topic(project, topic_name):
+def delete_topic(project_id, topic_name):
     """Deletes an existing Pub/Sub topic."""
     # [START pubsub_delete_topic]
+    from google.cloud import pubsub_v1
+
+    # TODO project_id = "Your Google Cloud Project ID"
+    # TODO topic_name = "Your Pub/Sub topic name"
+
     publisher = pubsub_v1.PublisherClient()
-    topic_path = publisher.topic_path(project, topic_name)
+    topic_path = publisher.topic_path(project_id, topic_name)
 
     publisher.delete_topic(topic_path)
 
     print('Topic deleted: {}'.format(topic_path))
     # [END pubsub_delete_topic]
 
 
-def publish_messages(project, topic_name):
+def publish_messages(project_id, topic_name):
     """Publishes multiple messages to a Pub/Sub topic."""
     # [START pubsub_quickstart_publisher]
     # [START pubsub_publish]
+    from google.cloud import pubsub_v1
+
+    # TODO project_id = "Your Google Cloud Project ID"
+    # TODO topic_name = "Your Pub/Sub topic name"
+
     publisher = pubsub_v1.PublisherClient()
-    topic_path = publisher.topic_path(project, topic_name)
+    # The `topic_path` method creates a fully qualified identifier
+    # in the form `projects/{project_id}/topics/{topic_name}`
+    topic_path = publisher.topic_path(project_id, topic_name)
 
     for n in range(1, 10):
         data = u'Message number {}'.format(n)
         # Data must be a bytestring
         data = data.encode('utf-8')
-        publisher.publish(topic_path, data=data)
+        # When you publish a message, the client returns a future.
+        future = publisher.publish(topic_path, data=data)
+        print('Published {} of message ID {}.'.format(data, future.result()))
 
     print('Published messages.')
     # [END pubsub_quickstart_publisher]
     # [END pubsub_publish]
 
 
-def publish_messages_with_custom_attributes(project, topic_name):
+def publish_messages_with_custom_attributes(project_id, topic_name):
     """Publishes multiple messages with custom attributes
     to a Pub/Sub topic."""
     # [START pubsub_publish_custom_attributes]
+    from google.cloud import pubsub_v1
+
+    # TODO project_id = "Your Google Cloud Project ID"
+    # TODO topic_name = "Your Pub/Sub topic name"
+
     publisher = pubsub_v1.PublisherClient()
-    topic_path = publisher.topic_path(project, topic_name)
+    topic_path = publisher.topic_path(project_id, topic_name)
 
     for n in range(1, 10):
         data = u'Message number {}'.format(n)
@@ -99,12 +124,17 @@ def publish_messages_with_custom_attributes(project, topic_name):
     # [END pubsub_publish_custom_attributes]
 
 
-def publish_messages_with_futures(project, topic_name):
+def publish_messages_with_futures(project_id, topic_name):
     """Publishes multiple messages to a Pub/Sub topic and prints their
     message IDs."""
     # [START pubsub_publisher_concurrency_control]
+    from google.cloud import pubsub_v1
+
+    # TODO project_id = "Your Google Cloud Project ID"
+    # TODO topic_name = "Your Pub/Sub topic name"
+
     publisher = pubsub_v1.PublisherClient()
-    topic_path = publisher.topic_path(project, topic_name)
+    topic_path = publisher.topic_path(project_id, topic_name)
 
     # When you publish a message, the client returns a Future. This Future
     # can be used to track when the message is published.
@@ -124,11 +154,18 @@ def publish_messages_with_futures(project, topic_name):
     # [END pubsub_publisher_concurrency_control]
 
 
-def publish_messages_with_error_handler(project, topic_name):
+def publish_messages_with_error_handler(project_id, topic_name):
     """Publishes multiple messages to a Pub/Sub topic with an error handler."""
     # [START pubsub_publish_messages_error_handler]
+    import time
+
+    from google.cloud import pubsub_v1
+
+    # TODO project_id = "Your Google Cloud Project ID"
+    # TODO topic_name = "Your Pub/Sub topic name"
+
     publisher = pubsub_v1.PublisherClient()
-    topic_path = publisher.topic_path(project, topic_name)
+    topic_path = publisher.topic_path(project_id, topic_name)
 
     def callback(message_future):
         # When timeout is unspecified, the exception method waits indefinitely.
@@ -155,17 +192,22 @@ def callback(message_future):
     # [END pubsub_publish_messages_error_handler]
 
 
-def publish_messages_with_batch_settings(project, topic_name):
+def publish_messages_with_batch_settings(project_id, topic_name):
     """Publishes multiple messages to a Pub/Sub topic with batch settings."""
     # [START pubsub_publisher_batch_settings]
-    # Configure the batch to publish once there is one kilobyte of data or
-    # 1 second has passed.
+    from google.cloud import pubsub_v1
+
+    # TODO project_id = "Your Google Cloud Project ID"
+    # TODO topic_name = "Your Pub/Sub topic name"
+
+    # Configure the batch to publish as soon as there is one kilobyte
+    # of data or one second has passed.
     batch_settings = pubsub_v1.types.BatchSettings(
         max_bytes=1024,  # One kilobyte
         max_latency=1,  # One second
     )
     publisher = pubsub_v1.PublisherClient(batch_settings)
-    topic_path = publisher.topic_path(project, topic_name)
+    topic_path = publisher.topic_path(project_id, topic_name)
 
     for n in range(1, 10):
         data = u'Message number {}'.format(n)
@@ -182,7 +224,7 @@ def publish_messages_with_batch_settings(project, topic_name):
         description=__doc__,
         formatter_class=argparse.RawDescriptionHelpFormatter
     )
-    parser.add_argument('project', help='Your Google Cloud project ID')
+    parser.add_argument('project_id', help='Your Google Cloud project ID')
 
     subparsers = parser.add_subparsers(dest='command')
     subparsers.add_parser('list', help=list_topics.__doc__)
@@ -220,18 +262,19 @@ def publish_messages_with_batch_settings(project, topic_name):
     args = parser.parse_args()
 
     if args.command == 'list':
-        list_topics(args.project)
+        list_topics(args.project_id)
     elif args.command == 'create':
-        create_topic(args.project, args.topic_name)
+        create_topic(args.project_id, args.topic_name)
     elif args.command == 'delete':
-        delete_topic(args.project, args.topic_name)
+        delete_topic(args.project_id, args.topic_name)
     elif args.command == 'publish':
-        publish_messages(args.project, args.topic_name)
+        publish_messages(args.project_id, args.topic_name)
     elif args.command == 'publish-with-custom-attributes':
-        publish_messages_with_custom_attributes(args.project, args.topic_name)
+        publish_messages_with_custom_attributes(
+            args.project_id, args.topic_name)
     elif args.command == 'publish-with-futures':
-        publish_messages_with_futures(args.project, args.topic_name)
+        publish_messages_with_futures(args.project_id, args.topic_name)
     elif args.command == 'publish-with-error-handler':
-        publish_messages_with_error_handler(args.project, args.topic_name)
+        publish_messages_with_error_handler(args.project_id, args.topic_name)
     elif args.command == 'publish-with-batch-settings':
-        publish_messages_with_batch_settings(args.project, args.topic_name)
+        publish_messages_with_batch_settings(args.project_id, args.topic_name)