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Installation

docs/basic/install.rst

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.. _installation:

Installation

In short, if you use one of the :ref:supported systems<supported-systems>, run::

pip install --upgrade pip
pip install "psycopg[binary]"

and you should be :ref:ready to start <module-usage>. Read further for alternative ways to install.

.. note:: Fun fact: there is no psycopg3 package, only psycopg!

.. _supported-systems:

Supported systems

The Psycopg version documented here has official and tested support for:

  • Python: from version 3.10 to 3.14

    • Python 3.8 and 3.9 are supported before Psycopg 3.3
    • Python 3.7 is supported before Psycopg 3.2
    • Python 3.6 is supported before Psycopg 3.1

  • PyPy: from version 3.10 to 3.11

    • PyPy 3.9 is supported before Psycopg 3.3
    • Note: Only the pure Python installation is currently supported.

  • PostgreSQL: from version 10 to 18

    • Note: PostgreSQL currently supported release__ are actively tested in the CI. Out-of-support releases are supported on a best-effort basis.

  • OS: Linux, macOS, Windows

  • Pip: 20.3 or newer

.. __: https://www.postgresql.org/support/versioning/

The tests to verify the supported systems run in Github workflows__: anything that is not tested there is not officially supported. This includes:

.. __: https://github.com/psycopg/psycopg/actions

  • Unofficial Python distributions such as Conda;
  • Alternative PostgreSQL implementation;
  • Other platforms such as BSD or Solaris.

If you use an unsupported system, things might work (because, for instance, the database may use the same wire protocol as PostgreSQL) but we cannot guarantee the correct working or a smooth ride.

.. _install-grid:

What to install?

There are a few different options to install Psycopg 3. This is a quick summary of their differences; follow the links for more details.

.. list-table:: :header-rows: 1

    • Installation Option
    • Command
    • Description
    • Perfor­mance
    • Needs Local libpq?
    • Needs Build Tools?
    • :ref:binary-installation (recommended for most users)
    • pip install psycopg[binary]
    • Precompiled C extensions, packaged with client libraries.
    • 🐇 Fast
    • ❌ No
    • ❌ No
    • :ref:local-installation
    • pip install psycopg[c]
    • Builds C extensions from source. Requires build tools and client libraries.
    • 🐇 Fast
    • ✅ Yes
    • ✅ Yes
    • :ref:pure-python-installation
    • pip install psycopg
    • Pure Python implementation only. Requires client libraries.
    • 🐢 Slow
    • ✅ Yes
    • ❌ No

.. _binary-installation:

Binary installation

The quickest way to start developing with Psycopg 3 is to install the binary packages by running::

pip install "psycopg[binary]"

This will install a self-contained package with all the libraries needed. If you are coming from Psycopg 2, this is the equivalent of installing the psycopg2-binary package.

.. seealso::

Did Psycopg 3 install ok? Great! You can now move on to the :ref:`basic
module usage <module-usage>` to learn how it works.

Keep on reading if the above method didn't work and you need a different
way to install Psycopg 3.

For further information about the differences between the packages see
:ref:`pq-impl`.

If your platform is not supported, or if the libpq packaged is not suitable, you should proceed to a :ref:local installation <local-installation> or a :ref:pure Python installation <pure-python-installation>.

.. note::

Binary packages are produced on a best-effort basis; the supported
platforms depend on the CI runners available to build the
packages. This means that:

- binary packages for a new version of Python are made available once
  the runners used for the build support it. You can check the
  `psycopg-binary PyPI files`__ to verify whether your platform is
  supported;

- the libpq version included in the binary packages depends on the version
  available on the runners. You can use the `psycopg.pq.version()`
  function and `~psycopg.pq.__build_version__` constant to infer the
  features available.

.. __: https://pypi.org/project/psycopg-binary/#files

.. warning::

- Starting from Psycopg 3.1.20, ARM64 macOS binary packages (i.e. for
  Apple M1 machines) are no more available for macOS versions before 14.0.
  Please upgrade your OS to at least 14.0 or use a :ref:`local
  <local-installation>` or a :ref:`Python <pure-python-installation>`
  installation.

- The binary installation is not supported by PyPy.

.. _local-installation:

Local installation

A "Local installation" results in a performing and maintainable library. The library will include the speed-up C module and will be linked to the system libraries (libpq, libssl...) so that system upgrade of libraries will upgrade the libraries used by Psycopg 3 too. This is the preferred way to install Psycopg for a production site.

In order to perform a local installation you need some prerequisites:

  • a C compiler,
  • Python development headers (e.g. the python3-dev package).
  • PostgreSQL client development headers (e.g. the libpq-dev package).
  • The :program:pg_config program available in the :envvar:PATH.

You must be able to troubleshoot an extension build, for instance you must be able to read your compiler's error message. If you are not, please don't try this and use the :ref:binary-installation instead.

If your build prerequisites are in place you can run::

pip install "psycopg[c]"

This will install a self-contained package with all the libraries needed. If you are coming from Psycopg 2, this is the equivalent of installing the psycopg2 package, both in terms of build requirements and system dependencies at runtime.

.. warning::

The local installation is not supported by PyPy.

.. _pure-python-installation:

Pure Python installation

If you simply install::

pip install psycopg

without [c] or [binary] extras you will obtain a pure Python implementation. This is particularly handy for debugging and hacking.

.. warning::

The pure Python installation is much slower than the :ref:binary-installation or :ref:local-installation. It is likely sufficient for local developments or small tasks but, for production loads, you might want to install one of the speed-up extensions too.

In order to use the pure Python installation you will need the libpq PostgreSQL client library installed on your client (which will be imported dynamically via ctypes); for example on Debian systems you will probably need::

sudo apt install libpq5

If you are not able to fulfill this requirement please use a :ref:binary-installation, which packages its own copy of the libpq.

.. note::

The ``libpq`` is the client library also used by :program:`psql`, the
PostgreSQL command line client, to connect to the database.  On most
systems, installing :program:`psql` will install the ``libpq`` too as a
dependency.

.. _pool-installation:

Installing the connection pool

The :ref:Psycopg connection pools <connection-pools> are distributed in a separate package from the !psycopg package itself, in order to allow a different release cycle.

In order to use the pool you must install the pool extra, using pip install "psycopg[pool]", or install the psycopg_pool package separately, which would allow to specify the release to install more precisely.

.. _install-dependencies:

Handling dependencies

If you need to specify your project dependencies (for instance in a requirements.txt file, setup.py, pyproject.toml dependencies...) you should probably specify one of the following:

  • If your project is a library, add a dependency on psycopg. This will make sure that your library will have the psycopg package with the right interface and leaves the possibility of choosing a specific implementation to the end user of your library.

  • If your project is a final application (e.g. a service running on a server) you can require a specific implementation, for instance psycopg[c], after you have made sure that the prerequisites are met (e.g. the depending libraries and tools are installed in the host machine).

In both cases you can specify which version of Psycopg to use using requirement specifiers__.

.. __: https://pip.pypa.io/en/stable/reference/requirement-specifiers/

If you want to make sure that a specific implementation is used you can specify the :envvar:PSYCOPG_IMPL environment variable: importing the library will fail if the implementation specified is not available. See :ref:pq-impl.