Supported Python Versions

Python >= 3.5

Deprecated Python Versions

Python == 2.7. Python 2.7 support will be removed on January 1, 2020.

Mac/Linux

pip install virtualenv
virtualenv <your-env>
source <your-env>/bin/activate
<your-env>/bin/pip install google-cloud-pubsub

Windows

pip install virtualenv
virtualenv <your-env>
<your-env>\Scripts\activate
<your-env>\Scripts\pip.exe install google-cloud-pubsub

Publishing

To publish data to Cloud Pub/Sub you must create a topic, and then publish messages to it

import os
from google.cloud import pubsub_v1

publisher = pubsub_v1.PublisherClient()
topic_name = 'projects/{project_id}/topics/{topic}'.format(
    project_id=os.getenv('GOOGLE_CLOUD_PROJECT'),
    topic='MY_TOPIC_NAME',  # Set this to something appropriate.
)
publisher.create_topic(topic_name)
publisher.publish(topic_name, b'My first message!', spam='eggs')

To learn more, consult the publishing documentation.

Subscribing

To subscribe to data in Cloud Pub/Sub, you create a subscription based on the topic, and subscribe to that, passing a callback function.

import os
from google.cloud import pubsub_v1

subscriber = pubsub_v1.SubscriberClient()
topic_name = 'projects/{project_id}/topics/{topic}'.format(
    project_id=os.getenv('GOOGLE_CLOUD_PROJECT'),
    topic='MY_TOPIC_NAME',  # Set this to something appropriate.
)
subscription_name = 'projects/{project_id}/subscriptions/{sub}'.format(
    project_id=os.getenv('GOOGLE_CLOUD_PROJECT'),
    sub='MY_SUBSCRIPTION_NAME',  # Set this to something appropriate.
)
subscriber.create_subscription(
    name=subscription_name, topic=topic_name)

def callback(message):
    print(message.data)
    message.ack()

future = subscriber.subscribe(subscription_name, callback)

The future returned by the call to subscriber.subscribe can be used to block the current thread until a given condition obtains:

try:
    future.result()
except KeyboardInterrupt:
    future.cancel()

To learn more, consult the subscriber documentation.