docs/installation.rst - cassandra-python-driver - Git at Google

 Installation
 ============

 Supported Platforms
 -------------------
 Python 3.9 through 3.13 are supported.  Both CPython (the standard Python
 implementation) and `PyPy <http://pypy.org>`_ are supported and tested.

 Linux, OSX, and Windows are supported.

 Installation through pip
 ------------------------
 `pip <https://pypi.org/project/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 <#optional-non-python-dependencies>`_ first. The driver may need to be reinstalled if dependencies are added after the initial installation.

 Verifying your Installation
 ---------------------------
 To check if the installation was successful, you can run::

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

 It should print something like "3.29.3".

 .. _installation-datastax-graph:

 (*Optional*) DataStax Graph
 ---------------------------
 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.

 (*Optional*) Compression Support
 --------------------------------
 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``.)

 (*Optional*) Metrics Support
 ----------------------------
 The driver has built-in support for capturing :attr:`.Cluster.metrics` about
 the queries you run.  However, the ``scales`` library is required to
 support this::

     pip install scales

 *Optional:* Column-Level Encryption (CLE) Support
 --------------------------------------------------
 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 <https://cryptography.io/en/latest/>`_ 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 <https://cryptography.io/en/latest/>`_ 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 <https://datastax-oss.atlassian.net/browse/PYTHON-1351>`_

 Speeding Up Installation
 ^^^^^^^^^^^^^^^^^^^^^^^^

 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>`.
 You can also use ``CASS_DRIVER_BUILD_CONCURRENCY`` to increase the number of
 threads used to build the driver and any C extensions:

 .. code-block:: bash

     $ # installing from source
     $ CASS_DRIVER_BUILD_CONCURRENCY=8 python setup.py install
     $ # installing from pip
     $ CASS_DRIVER_BUILD_CONCURRENCY=8 pip install cassandra-driver

 OSX Installation Error
 ^^^^^^^^^^^^^^^^^^^^^^
 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:

 .. code-block:: bash

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

 .. _windows_build:

 Windows Installation Notes
 --------------------------
 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 <http://aka.ms/vcpython27>`_
 (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).

 Manual Installation
 -------------------
 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 <https://github.com/datastax/python-driver/blob/master/requirements.txt>`_.

 Once the dependencies are installed, simply run::

     python setup.py install


 (*Optional*) Non-python Dependencies
 ------------------------------------
 The driver has several **optional** features that have non-Python dependencies.

 C Extensions
 ^^^^^^^^^^^^
 By default, a number of extensions are compiled, providing faster hashing
 for token-aware routing with the ``Murmur3Partitioner``,
 `libev <http://software.schmorp.de/pkg/libev.html>`_ event loop integration,
 and Cython optimized extensions.

 When installing manually through setup.py, you can disable both with
 the ``--no-extensions`` option, or selectively disable them with
 with ``--no-murmur3``, ``--no-libev``, or ``--no-cython``.

 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.

 .. _cython-extensions:

 Cython-based Extensions
 ~~~~~~~~~~~~~~~~~~~~~~~
 By default, this package uses `Cython <http://cython.org/>`_ to optimize core modules and build custom extensions.
 This is not a hard requirement, but is engaged by default to build extensions offering better performance than the
 pure Python implementation.

 This is a costly build phase, especially in clean environments where the Cython compiler must be built
 This build phase can be avoided using the build switch, or an environment variable::

     python setup.py install --no-cython

 Alternatively, an environment variable can be used to switch this option regardless of
 context::

     CASS_DRIVER_NO_CYTHON=1 <your script here>
     - or, to disable all extensions:
     CASS_DRIVER_NO_EXTENSIONS=1 <your script here>

 This method is required when using pip, which provides no other way of injecting user options in a single command::

     CASS_DRIVER_NO_CYTHON=1 pip install cassandra-driver
     CASS_DRIVER_NO_CYTHON=1 sudo -E pip install ~/python-driver

 The environment variable is the preferred option because it spans all invocations of setup.py, and will
 prevent Cython from being materialized as a setup requirement.

 If your sudo configuration does not allow SETENV, you must push the option flag down via pip. However, pip
 applies these options to all dependencies (which break on the custom flag). Therefore, you must first install
 dependencies, then use install-option::

     sudo pip install futures
     sudo pip install --install-option="--no-cython"


 Supported Event Loops
 ^^^^^^^^^^^^^^^^^^^^^
 For Python versions before 3.12 the driver uses the ``asyncore`` module for its default
 event loop.  Other event loops such as ``libev``, ``gevent`` and ``eventlet`` are also
 available via Python modules or C extensions.  Python 3.12 has removed ``asyncore`` entirely
 so for this platform one of these other event loops must be used.

 libev support
 ^^^^^^^^^^^^^
 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 <http://brew.sh/>`_. 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 <https://vcpkg.io>`_::

     $ vcpkg install libev

 If successful, you should be able to build and install the extension
 (just using ``setup.py build`` or ``setup.py install``) and then use
 the libev event loop by doing the following:

 .. code-block:: python

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

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

 (*Optional*) Configuring SSL
 -----------------------------
 Andrew Mussey has published a thorough guide on
 `Using SSL with the DataStax Python driver <http://blog.amussey.com/post/64036730812/cassandra-2-0-client-server-ssl-with-datastax-python>`_.
	Installation
	============

	Supported Platforms
	-------------------
	Python 3.9 through 3.13 are supported. Both CPython (the standard Python
	implementation) and `PyPy <http://pypy.org>`_ are supported and tested.

	Linux, OSX, and Windows are supported.

	Installation through pip
	------------------------
	`pip <https://pypi.org/project/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 <#optional-non-python-dependencies>`_ first. The driver may need to be reinstalled if dependencies are added after the initial installation.

	Verifying your Installation
	---------------------------
	To check if the installation was successful, you can run::

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

	It should print something like "3.29.3".

	.. _installation-datastax-graph:

	(Optional) DataStax Graph
	---------------------------
	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.

	(Optional) Compression Support
	--------------------------------
	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``.)

	(Optional) Metrics Support
	----------------------------
	The driver has built-in support for capturing :attr:`.Cluster.metrics` about
	the queries you run. However, the ``scales`` library is required to
	support this::

	pip install scales

	Optional: Column-Level Encryption (CLE) Support
	--------------------------------------------------
	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 <https://cryptography.io/en/latest/>`_ 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 <https://cryptography.io/en/latest/>`_ 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 <https://datastax-oss.atlassian.net/browse/PYTHON-1351>`_

	Speeding Up Installation
	^^^^^^^^^^^^^^^^^^^^^^^^

	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>`.
	You can also use ``CASS_DRIVER_BUILD_CONCURRENCY`` to increase the number of
	threads used to build the driver and any C extensions:

	.. code-block:: bash

	$ # installing from source
	$ CASS_DRIVER_BUILD_CONCURRENCY=8 python setup.py install
	$ # installing from pip
	$ CASS_DRIVER_BUILD_CONCURRENCY=8 pip install cassandra-driver

	OSX Installation Error
	^^^^^^^^^^^^^^^^^^^^^^
	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:

	.. code-block:: bash

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

	.. _windows_build:

	Windows Installation Notes
	--------------------------
	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 <http://aka.ms/vcpython27>`_
	(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).

	Manual Installation
	-------------------
	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 <https://github.com/datastax/python-driver/blob/master/requirements.txt>`_.

	Once the dependencies are installed, simply run::

	python setup.py install


	(Optional) Non-python Dependencies
	------------------------------------
	The driver has several optional features that have non-Python dependencies.

	C Extensions
	^^^^^^^^^^^^
	By default, a number of extensions are compiled, providing faster hashing
	for token-aware routing with the ``Murmur3Partitioner``,
	`libev <http://software.schmorp.de/pkg/libev.html>`_ event loop integration,
	and Cython optimized extensions.

	When installing manually through setup.py, you can disable both with
	the ``--no-extensions`` option, or selectively disable them with
	with ``--no-murmur3``, ``--no-libev``, or ``--no-cython``.

	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.

	.. _cython-extensions:

	Cython-based Extensions
	~~~~~~~~~~~~~~~~~~~~~~~
	By default, this package uses `Cython <http://cython.org/>`_ to optimize core modules and build custom extensions.
	This is not a hard requirement, but is engaged by default to build extensions offering better performance than the
	pure Python implementation.

	This is a costly build phase, especially in clean environments where the Cython compiler must be built
	This build phase can be avoided using the build switch, or an environment variable::

	python setup.py install --no-cython

	Alternatively, an environment variable can be used to switch this option regardless of
	context::

	CASS_DRIVER_NO_CYTHON=1 <your script here>
	- or, to disable all extensions:
	CASS_DRIVER_NO_EXTENSIONS=1 <your script here>

	This method is required when using pip, which provides no other way of injecting user options in a single command::

	CASS_DRIVER_NO_CYTHON=1 pip install cassandra-driver
	CASS_DRIVER_NO_CYTHON=1 sudo -E pip install ~/python-driver

	The environment variable is the preferred option because it spans all invocations of setup.py, and will
	prevent Cython from being materialized as a setup requirement.

	If your sudo configuration does not allow SETENV, you must push the option flag down via pip. However, pip
	applies these options to all dependencies (which break on the custom flag). Therefore, you must first install
	dependencies, then use install-option::

	sudo pip install futures
	sudo pip install --install-option="--no-cython"


	Supported Event Loops
	^^^^^^^^^^^^^^^^^^^^^
	For Python versions before 3.12 the driver uses the ``asyncore`` module for its default
	event loop. Other event loops such as ``libev``, ``gevent`` and ``eventlet`` are also
	available via Python modules or C extensions. Python 3.12 has removed ``asyncore`` entirely
	so for this platform one of these other event loops must be used.

	libev support
	^^^^^^^^^^^^^
	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 <http://brew.sh/>`_. 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 <https://vcpkg.io>`_::

	$ vcpkg install libev

	If successful, you should be able to build and install the extension
	(just using ``setup.py build`` or ``setup.py install``) and then use
	the libev event loop by doing the following:

	.. code-block:: python

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

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

	(Optional) Configuring SSL
	-----------------------------
	Andrew Mussey has published a thorough guide on
	`Using SSL with the DataStax Python driver <http://blog.amussey.com/post/64036730812/cassandra-2-0-client-server-ssl-with-datastax-python>`_.