Redis Pub/Sub

Learn about Redis pub/sub and how to use it with Python.

By Kevin McAleer,    3 Minutes

Overview

In this lesson, we will cover Redis pub/sub and how to use it with Python. Redis pub/sub is a messaging system that allows for publish/subscribe messaging between clients. We will cover how to publish and subscribe to channels in Redis, and how to use pub/sub in Python.

Lesson Content

In this lesson, we will cover:

• Redis pub/sub
• Publishing messages to channels
• Subscribing to channels
• Using Redis pub/sub with Python

Redis Pub/Sub

Redis pub/sub is a messaging system that allows for publish/subscribe messaging between clients. In pub/sub, there are publishers and subscribers. Publishers send messages to channels, and subscribers receive messages from channels.

Publishing Messages to Channels

To publish a message to a channel in Redis, you can use the publish command. Here’s an example of how to publish a message to a channel:

publish mychannel "Hello, world!"
(integer) 1

Subscribing to Channels

To subscribe to a channel in Redis, you can use the subscribe command. Here’s an example of how to subscribe to a channel:

subscribe mychannel
Reading messages... (press Ctrl-C to quit)

1. "subscribe"
2. "mychannel"
3. (integer) 1

Once you have subscribed to a channel, you will receive any messages that are published to that channel.

Using Redis Pub/Sub with Python

To use Redis pub/sub in Python, you can use the pubsub methods of the Redis Python library. Here’s an example of how to use Redis pub/sub in Python:

import redis

redis_client = redis.Redis(host='localhost', port=6379)

# Publish a message to a channel
redis_client.publish('mychannel', 'Hello, world!')

# Subscribe to a channel
pubsub = redis_client.pubsub()
pubsub.subscribe('mychannel')

# Receive messages from the subscribed channel
for message in pubsub.listen():
    print(message)

In this example, we use the Redis Python library to publish a message to a channel using the publish method, subscribe to a channel using the subscribe method, and receive messages from the subscribed channel using a for loop.

Key Takeaways

After completing this lesson, you should be able to:

• Describe Redis pub/sub and its implementation in Redis
• Publish messages to channels in Redis
• Subscribe to channels in Redis and receive messages
• Use Redis pub/sub in Python

Conclusion

In this lesson, we covered Redis pub/sub and how to use it with Python. We described Redis pub/sub and its implementation in Redis, and demonstrated how to publish messages to channels and subscribe to channels in Redis, and how to use Redis pub/sub in Python using the Redis Python library. In the final lesson, we will review what we have learned and provide some additional resources for further study.