The Google development team tell us about this service:
The Google Cloud Pub/Sub service allows applications to exchange messages reliably, quickly, and asynchronously. To accomplish this, a producer of data publishes a message to a Cloud Pub/Subtopic. A subscriber client then creates a subscription to that topic and consumes messages from the subscription. Cloud Pub/Sub persists messages that could not be delivered reliably for up to seven days. This page shows you how to get started publishing messages with Cloud Pub/Sub using client libraries.
The simple idea about this is:
Publisher applications can send messages to a topic, and other applications can subscribe to that topic to receive the messages.
I start with the installation of the python module using python version 2.7 and pip tool.
C:\Python27>cd Scripts
C:\Python27\Scripts>pip install --upgrade google-cloud-pubsub
Collecting google-cloud-pubsub
Downloading google_cloud_pubsub-0.28.4-py2.py3-none-any.whl (79kB)
100% |################################| 81kB 300kB/s
...
Successfully installed google-cloud-pubsub-0.28.4 grpc-google-iam-v1-0.11.4 ply-3.8
psutil-5.4.0 pyasn1-modules-0.1.5 setuptools-36.6.0
The default settings can be started and set with this command: gcloud init .
You need to edit this settings and app.yaml at ~/src/.../appengine/flexible/pubsub$ nano app.yaml.
After that, you set all of this using the command gcloud app deploy you can see the output at https://[YOUR_PROJECT_ID].appspot.com.
The main goal of this tutorial was to start and run the Google Cloud Pub/Sub service with python and this has been achieved.