title	description	tags
Pulsar Python Tutorial.	Learn how to create Pulsar applications in Python.	pulsar tutorial python producer consumer

Getting started with Pulsar in Python

In this tutorial, we will create two Python scripts that can send and receive messages through a Pulsar topic.

We will start a local Pulsar cluster and test the scripts in a live cluster.

Start Pulsar standalone

A very convenient way to start playing with Pulsar is to start a standalone service. That includes a complete Pulsar-cluster in a single JVM instance.

There are few ways to get a Pulsar standalone cluster up and running:

• Using binary releases: Local cluster documentation
• Using Docker: Pulsar in Docker

If you are in MacOS, you can even use Homebrew to install a local Pulsar cluster for testing purposes:

# Register tap
$ brew tap streamlio/homebrew-formulae

# Install
brew install streamlio/homebrew-formulae/pulsar

# Start the Pulsar standalone as a background service
brew services start pulsar

Requirements for the Python client

The Pulsar Python client library can be installed directly from PyPI.

OS	Versions	Python versions
Linux	Ubuntu, CentOS, Debian and most others	2.7, 3.3, 3.4, 3.5, 3.6
MacOS	10.11 (El capitan), 10.12 (Sierra)	2.7, 3.6

$ pip install pulsar-client

Clone the project

From the command line, use the following Git command to clone this project:

$ git clone https://github.com/streamlio/pulsar-python-tutorial.git

This command creates a directory named pulsar-python-tutorial at the current location, which contains the tutorial basic Pulsar client Python project. The pulsar-python-tutorial directory contains the following items:

File or directory	Description
consumer_tutorial.py	Consumer tuorial code
producer_tutorial.py	Producer tuorial code

Consumer

The first step is to start a consumer. This will create a subscription and make sure that every message published after that is going to be retained by Pulsar, until an explicit acknowledgment of the message processing is received.

The consumer code is available at consumer_tutorial.py. The sample code is very simple:

import pulsar

# Create a Pulsar client instance. The instance can be shared across multiple
# producers and consumers
client = pulsar.Client('pulsar://localhost:6650')

# Subscribe to the topic. If the topic does not exist, it will be
# automatically created
consumer = client.subscribe('persistent://sample/standalone/ns1/my-topic',
                            'my-subscription')

while True:
    try:
        # try and receive messages with a timeout of 10 seconds
        msg = consumer.receive(timeout_millis=10000)

        # Do something with the message
        print("Received message '%s'", msg.data())

        # Acknowledge processing of message so that it can be deleted
        consumer.acknowledge(msg)
    except Exception:
        print("No message received in the last 10 seconds")

client.close()

You can start the consumer with:

python consumer_tutorial.py

Producer

The next step is to start the producer. In this example, we will start ingesting sample data into a topic where the consumer has already created a subscription.The producer code is available at producer_tutorial.py:

import pulsar

# Create a Pulsar client instance. The instance can be shared across multiple
# producers and consumers
client = pulsar.Client('pulsar://localhost:6650')

# Create a producer on the topic. If the topic doesn't exist
# it will be automatically created
producer = client.create_producer(
                'persistent://sample/standalone/ns1/my-topic')

for i in range(10):
    content = 'hello-pulsar-%d' % i
    # Publish a message and wait until it is persisted
    producer.send(content)
    print('Published message: "%s"' % content)

client.close()

You can start the producer with:

python producer_tutorial.py

At this point you should see the consumer to start receiving the published sample messages.

You can find more documentation for Pulsar Python client at https://pulsar.incubator.apache.org/docs/latest/clients/Python/ and the complete API reference at https://pulsar.incubator.apache.org/api/python/.