species is compatible with Python 3.7/3.8/3.9 and is available in the PyPI repository and on Github.

Installation from PyPI

The Python package can be installed with the pip package manager:

$ pip install species

Or, to update to the most recent version:

$ pip install --upgrade species

Please check for any errors and warnings during the installation to make sure that all dependencies are correctly installed.


Before installing species, it is required to separately install cython:

$ pip install cython


The PyMultiNest package requires the manual installation of MultiNest. Please follow the instructions for the building the library and make sure that the LD_LIBRARY_PATH (on Linux) or DYLD_LIBRARY_PATH (on macOS) environment variable is set. It is also possible to use species without installing MultiNest (but a warning will appear), apart from the functionalities that rely on PyMultiNest.

Installation from Github

Installation from Github is done by cloning the repository:

$ git clone

And running the setup script to install the package and its dependencies:

$ python install


If an error occurs when running then possibly pip needs to be updated to the latest version:

$ pip install --upgrade pip

Alternatively to running the file, the folder where species is located can also be added to the PYTHONPATH environment variable such that the package is found by Python. The command may depend on the OS that is used, but is typically something like:

$ export PYTHONPATH=$PYTHONPATH:/path/to/species

New commits can be pulled from Github once a local copy of the repository exists:

$ git pull origin main

Do you want to make changes to the code? Please fork the species repository on the Github page and clone your own fork instead of the main repository. Contributions and pull requests are very welcome (see Contributing section).

Testing species

The installation can now be tested, for example by starting Python in interactive mode and printing the version number of the installed package:

>>> import species
>>> species.__version__