psycopg3 is a modern implementation of a PostgreSQL adapter for Python.

The library is still in a development stage and is not available on PyPI in the form of packages yet. You can install it directly from the GitHub project:

$ pip install git+https://github.com/psycopg/psycopg3.git#subdirectory=psycopg3
$ python3
>>> import psycopg3

You are required to have the libpq, the PostgreSQL client library, already installed in the system before using psycopg3. On Debian system you can obtain it by running:

sudo apt-get install libpq5

Please check your system's documentation for information about installing the libpq on your platform.

In order to work on the psycopg3 source code you should clone this repository:

git clone https://github.com/psycopg/psycopg3.git
cd psycopg3

Please note that the repository contains the source code of several Python packages: that's why you don't see a setup.py here. The packages may have different requirements:

• The psycopg3 directory contains the pure python implementation of psycopg3. The package has only a runtime dependency on the libpq, the PostgreSQL client library, which should have been already installed in your system.
• The psycopg3_c directory contains an optimization module written in C/Cython. In order to build it you will need a few development tools: please look at Local installation in the docs for the details.

You can create a local virtualenv and install there the packages in development mode, together with their development and testing requirements:

python -m venv .venv
source .venv/bin/activate
pip install -e ./psycopg3[dev,test]     # for the base Python package
pip install -e ./psycopg3_c             # for the C extension module

Now hack away! You can use tox to validate the code:

pip install tox
tox -p4

and to run the tests:

psql -c 'create database psycopg3_test'
export PSYCOPG3_TEST_DSN="dbname=psycopg3_test"
tox -c psycopg3 -s
tox -c psycopg3_c -s

Please look at the commands definitions in the tox.ini files if you want to run some of them interactively: the dependency should be already in your virtualenv. Feel free to adapt these recipes if you follow a different development pattern.