Python Client

Overview

This section provides information about the Python client for Hazelcast, and explains how to install and use the client.

tip

To learn how to get started quickly with the Hazelcast Python client, follow our simple Get started with Python tutorial.

The Hazelcast native Python client is an official library that allows Python applications to connect to and interact with Hazelcast clusters. It is implemented using the Hazelcast Open Binary Client Protocol. The key features and benefits include:

• Distributed data structures: the client provides access to Hazelcast's distributed data structures such as maps, queues, topics, lists, sets, and more.
• SQL support: it offers the ability to query Map data using standard SQL syntax.
• JSON object support: it allows using and querying JSON objects.
• Compact serialization: the client supports compact serialization, which provides efficient serialization of objects.
• DBAPI support: it implements the DBAPI interface on top of the SQL service, making it compatible with various libraries and tools.
• Near cache: the client supports the near cache feature for faster reads on frequently accessed data.

These features make the Hazelcast Python Client a powerful tool for Python applications requiring distributed computing, in-memory data processing, and real-time analytics capabilities.

tip

For the latest Python API documentation, see Hazelcast Python Client docs.

Install the Python client

This section explains how to set up a Hazelcast cluster and install the Hazelcast Python client.

Set up a Hazelcast cluster

The Hazelcast Python client requires a working Hazelcast cluster to run. The cluster handles storage and manipulation of the user data. Clients are a way to connect to the Hazelcast cluster and access the data.

The quickest way to start a single member cluster for development purposes is to use our Docker images.

Launch a Hazelcast Docker Container by running the following command:

bash

docker run -p 5701:5701 hazelcast/hazelcast

tip

For a step-by-step guide, see the Start a local cluster in Docker and Get Started with Hazelcast Enterprise Edition tutorials.

Alternatively, you can run standalone members by downloading and running distribution files from the Hazelcast website as follows:

1. Go to the download page and choose either the ZIP or TAR distribution of Hazelcast.
2. Decompress the contents into the directory that you want to run members from.
3. Change into this directory and then start the Hazelcast member using the bin/hz-start script.

The Hazelcast log appears in the terminal showing that your 1-member cluster is ready to be used.

For more information on setting up a Hazelcast cluster, see the Python client documentation.

Download and install the client

You can download and install the Python client from PyPI (the Python Package Index) using pip. This library allows your Python applications to connect to and interact with a Hazelcast cluster, enabling you to use distributed data structures and other Hazelcast features in your Python code.

To download and install the client, run:

bash

pip install hazelcast-python-client

Use the client

This section shows how to connect to a Hazelcast cluster and perform some basic operations using the client.

Example: Connect to a Hazelcast cluster

python

    import hazelcast

    client = hazelcast.HazelcastClient()

Example: Get or create the "distributed-map" on the cluster

python

    distributed_map = client.get_map("distributed-map")

Example: Put "key", "value" pair into the "distributed-map"

In this example, you will have to wait for the request to complete.

python

    distributed_map.set("key", "value").result()

Example: Get the value associated with the given key from the cluster

In this example, you will attach a callback to be executed once the response for the get request is received. Note that, the set request above is blocking since it calls ".result()" on the returned Future, whereas the get request below is non-blocking.

python

    get_future = distributed_map.get("key")
    get_future.add_done_callback(lambda future: print(future.result()))

Note that further operations will not wait for the get request above to complete.

Example: Print the map and shut down the client

python

    print("Map size:", distributed_map.size().result())
    client.shutdown()

For more code samples, see the Hazelcast Python examples.

Configure the client

If you are running Hazelcast and the Python client on the same machine, the default configuration should work out-of-the-box. However, if you run the client on a different computer to that of the cluster members, you may need to do some simple configuration, such as specifying member addresses, or customizing client properties.

The following shows some basic configuration settings:

python

    import hazelcast

    client = hazelcast.HazelcastClient(
        cluster_name="cluster-name",
        cluster_members=[
            "10.90.0.2:5701",
            "10.90.0.3:5701",
        ],
        lifecycle_listeners=[
            lambda state: print("Lifecycle event >>>", state),
        ]
    )

    print("Connected to cluster")
    client.shutdown()

For detailed network configurations and additional features of Hazelcast Python client configuration, see the Configuration overview and Configuring Hazelcast Python client.

Get support

Join us in the Python client channel. Get an invite via Slack.

Raise an issue in the GitHub repository.

Next steps

For more information:

• See the Hazelcast Python Client GitHub repo
• Find code samples