For the latest release, use:

pip install Pyrseas

For development:

git clone git://
cd Pyrseas
python install


Pyrseas provides tools for Postgres, so obviously you need Postgres to start with. Pyrseas has been tested with PG 9.3, 9.4, 9.5, 9.6 and 10, and we’ll certainly keep up with future releases. Please refer to the Postgres download page to find a distribution for the various Linux, Unix and Windows platforms supported.

You will also need Python. Pyrseas was originally developed using Python 2 and been tested with Python 2.7, but may also work under 2.6. It has been ported to Python 3 and tested against versions from 3.2 through 3.6. Python 3 is the preferred usage and development environment. On Linux or *BSD, Python may already be part of your distribution or may be available as a package. For Windows and Mac OS please refer to the Python download page for installers and instructions.

Pyrseas talks to the Postgres DBMS via the Psycopg2 adapter. Pyrseas has been tested with psycopg2 2.5 through 2.7. Psycopg2 is available as a package on most Linux or *BSD distributions and can also be downloaded or installed from PyPI. Please refer to the Psycopg download page for more details.


If you install Pyrseas using pip (see below) and you have not already installed Psycopg2, e.g., when installing into a virtualenv environment created with --no-site-packages, you may need to have installed the Postgres and Python development packages, and a C compiler, as pip may download and attempt to build and install psycopg2 before installing Pyrseas.

The Pyrseas utilities rely on PyYAML, a YAML library. This may be available as a package for your operating system or it can be downloaded from the Python Package Index (PyPI).

The utilities also rely on PgDbConn, an offshoot of the project that generalizes the Postgres database connection code used in the utilities. It can be downloaded from PyPI.


Pyrseas is available at the following locations:

You can download the distribution from PyPI in gzip-compressed tar or ZIP archive format, but you can download and install it using Pip. See Python Installer below for details.

PGXN provides a ZIP archive which you can download or you can download and install using the PGXN client (see PGXN Client below).

The GitHub repository holds the Pyrseas source code, tagged according to the various releases, e.g., v0.8.0, and including unreleased modifications. To access it, you need Git which is available as a package in most OS distributions or can be downloaded from the Git download page. You can fetch the Pyrseas sources by issuing one of the following commands:

git clone git://


git clone

This will create a Pyrseas directory tree (you can use a different target name by adding it to the above commands). To list available releases, change to the subdirectory and invoke git tag. To switch to a particular release, use:

git checkout vn.n.n

where vn.n.n is the release identifier. Use git checkout master to revert to the main (master) branch. To fetch the latest updates, use:

git pull


Extracting Sources

Once you have downloaded an archive from PyPI or PGXN, you need to extract the sources. For a gzip-compressed tar file, use:

tar xzf Pyrseas-n.n.n.tar.gz

where n.n.n is the release version. For a ZIP archive, use:


Both commands above will create a directory Pyrseas-n.n.n and you will want to cd to it before proceeding with the installation.


If you have superuser or similar administrative privileges, you can install Pyrseas for access by multiple users on your system. On Linux and other Unix-flavored systems, you can install from the extracted Pyrseas-n.n.n source directory or from the root directory of the git clone, using the following command:

sudo python install

That will install the dbtoyaml and yamltodb utility scripts in a directory such as /usr/local/bin. The library sources and bytecode files will be placed in a pyrseas subdirectory under site-packages or dist-packages, e.g., /usr/local/lib/python3.6/dist-packages/pyrseas.

On Windows, from an account with Administrator privileges, you can use:

python install

That will install the Pyrseas utilities in the Scripts folder of your Python installation. The source and bytecode files will go in the site-packages folder, e.g., C:\Python36\Lib\site-packages\pyrseas.

Python Installer

You can also download and install Pyrseas using pip. For example, on Linux do:

sudo pip install Pyrseas

If this is the first time you are installing a Python package, please do yourself a favor and read and follow the instructions in the “Distribute & Pip” subsection of the “Installing Python on ...” section for your platform of the The Hitchhiker’s Guide to Python!.


On FreeBSD, it has been reported that it is necessary to install the Python distribute package, prior to installing Pyrseas with pip. This may also be necessary on other BSD variants.


On Windows 64-bit, it has been reported that it is necessary to obtain unofficial versions of the distribute and PyYAML packages, available at University of California, Irvine. For a detailed tutorial, see this post.

Pip can also be used in a Python virtualenv environment, in which case you don’t need to prefix the commands with sudo.

Pip also provides the ability to uninstall Pyrseas.

PGXN Client

The PGXN client (available at PyPI) can be used to download and install Pyrseas from PGXN. Usage is:

pgxn install pyrseas