Python 3.10 through 3.14 are supported. Both CPython (the standard Python implementation) and PyPy are supported and tested.

Linux, OSX, and Windows are supported.

pip is the suggested tool for installing packages. It will handle installing all Python dependencies for the driver at the same time as the driver itself. To install the driver*:

pip install cassandra-driver

You can use pip install --pre cassandra-driver if you need to install a beta version.

*Note: if intending to use optional extensions, install the dependencies first. The driver may need to be reinstalled if dependencies are added after the initial installation.

To check if the installation was successful, you can run:

python -c 'import cassandra; print(cassandra.__version__)'

This command should print something like 3.30.0.

The driver provides an optional fluent graph API that depends on Apache TinkerPop (gremlinpython). It is not installed by default. To be able to build Gremlin traversals, you need to install the graph extra:

pip install cassandra-driver[graph]

See :doc:`graph_fluent` for more details about this API.

Compression can optionally be used for communication between the driver and Cassandra. There are currently two supported compression algorithms: snappy (in Cassandra 1.2+) and LZ4 (only in Cassandra 2.0+). If either is available for the driver and Cassandra also supports it, it will be used automatically.

For lz4 support:

pip install lz4

For snappy support:

pip install python-snappy

(If using a Debian Linux derivative such as Ubuntu, it may be easier to just run apt-get install python-snappy.)

The driver has built-in support for capturing :attr:`.Cluster.metrics` about the queries you run. Note that the scales module is required to support metrics. This module is available from Pypi and can be installed with:

pip install scales

The driver has built-in support for client-side encryption and decryption of data. For more, see :doc:`column_encryption`.

CLE depends on the Python cryptography module. When installing Python driver 3.27.0. the cryptography module is also downloaded and installed. If you are using Python driver 3.28.0 or later and want to use CLE, you must install the cryptography module.

You can install this module along with the driver by specifying the cle extra:

pip install cassandra-driver[cle]

Alternatively, you can also install the module directly via pip:

pip install cryptography

Any version of cryptography >= 35.0 will work for the CLE feature. You can find additional details at PYTHON-1351

By default, installing the driver through pip uses a pre-compiled, platform-specific wheel when available. If using a source distribution rather than a wheel, Cython is used to compile certain parts of the driver. This makes those hot paths faster at runtime, but the Cython compilation process can take a long time -- as long as 10 minutes in some environments.

In environments where performance is less important, it may be worth it to :ref:`disable Cython as documented below <cython-extensions>`.

Cython also supports concurrent builds of native extensions. The build-concurrency key in the tool.cassandra-driver table of pyproject.toml is an integer value which specifies the number of concurrent builds Cython may execute. The value for this key must be a non-negative integer; the default is zero, indicating no concurrent builds. Note that Cython's concurrent builds use the standard multiprocessing package so this library must be availble is concurrent builds are used.

If you're installing on OSX and have XCode 5.1 installed, you may see an error like this:

clang: error: unknown argument: '-mno-fused-madd' [-Wunused-command-line-argument-hard-error-in-future]

To fix this, re-run the installation with an extra compilation flag:

ARCHFLAGS=-Wno-error=unused-command-line-argument-hard-error-in-future pip install cassandra-driver

Installing the driver with extensions in Windows sometimes presents some challenges. A few notes about common hang-ups:

Setup requires a compiler. When using Python 2, this is as simple as installing this package (this link is also emitted during install if setuptools is unable to find the resources it needs). Depending on your system settings, this package may install as a user-specific application. Make sure to install for everyone, or at least as the user that will be building the Python environment.

It is also possible to run the build with your compiler of choice. Just make sure to have your environment setup with the proper paths. Make sure the compiler target architecture matches the bitness of your Python runtime. Perhaps the easiest way to do this is to run the build/install from a Visual Studio Command Prompt (a shortcut installed with Visual Studio that sources the appropriate environment and presents a shell).

You can always install the driver directly from a source checkout or tarball. When installing manually, ensure the python dependencies are already installed. You can find the list of dependencies in requirements.txt.

Once the dependencies are installed, simply run:

pip install .

The driver has several optional features that have non-Python dependencies.

By default, a number of extensions are compiled, providing faster hashing for token-aware routing with the Murmur3Partitioner, libev event loop integration, and Cython optimized extensions.

Some or all of these native extensions can be disabled by changing the corresponding key in the tool.cassandra-driver table of pyproject.toml to false. Please consult the build-murmur3-extension, build-libev-extension and build-cython-extensions keys (respectively) to disable these extensions.

To compile the extensions, ensure that GCC and the Python headers are available.

On Ubuntu and Debian, this can be accomplished by running:

$ sudo apt-get install gcc python-dev

On RedHat and RedHat-based systems like CentOS and Fedora:

$ sudo yum install gcc python-devel

On OS X, homebrew installations of Python should provide the necessary headers.

See :ref:`windows_build` for notes on configuring the build environment on Windows.

By default, this package uses Cython to optimize core modules and build custom extensions. This is not a hard requirement, but is enabled by default to build extensions offering better performance than the pure Python implementation.

This process does take some time, however, so if you wish to build without generating these extensions using Cython you can do so by changing the build-cython-extensions key in the tool.cassandra-driver table of pyproject.toml. By default this key is set to true; simply changing it to false will disable all Cython functionality.

The asyncore and libev event loops are proven production-grade event loops. Python 3.12 removed asyncore from the runtime but this event loop can still be used in newer versions of Python via the pyasyncore package.

The asyncio event loop is generally functional but still somewhat experimental and not recommended for production systems. We anticipate significant improvements to this event loop (including hopefully making this event loop the default going forward) in 3.31.0.

The gevent, eventlet and Twisted event loops have been deprecated in 3.30.0 and will be removed completely in 3.31.0.

If you're on Linux, you should be able to install libev through a package manager. For example, on Debian/Ubuntu:

$ sudo apt-get install libev4 libev-dev

On RHEL/CentOS/Fedora:

$ sudo yum install libev libev-devel

If you're on Mac OS X, you should be able to install libev through Homebrew. For example, on Mac OS X:

$ brew install libev

The libev extension can now be built for Windows as of Python driver version 3.29.2. You can install libev using any Windows package manager. For example, to install using vcpkg:

$ vcpkg install libev

If successful, you should be able to build and install the extension (just using pip install or pip install -e) and then use the libev event loop by doing the following:

>>> from cassandra.io.libevreactor import LibevConnection
>>> from cassandra.cluster import Cluster

>>> cluster = Cluster()
>>> cluster.connection_class = LibevConnection
>>> session = cluster.connect()

Andrew Mussey has published a thorough guide on Using SSL with the DataStax Python driver.