classylss is currently supported on macOS and Linux architectures. The recommended installation method uses the Anaconda Python distribution. The package is available for Python versions 2.7, 3.5, and 3.6.

Installing with Anaconda

The easiest installation method uses the conda utility, as part of the Anaconda package manager. The distribution can be downloaded and installed for free from The package can be installed into the user’s current conda environment using:

conda install -c bccp classylss

Installing from Source


The easiest and recommended method to install classylss is using the Anaconda package, which provides pre-built binaries for Linux and macOS machines. See Installing with Anaconda for more details.

The package can be installed (and compiled locally) via the pip command

pip install classylss

Users can also downloaded the source code from GitHub using

git clone
cd classylss

These installation methods require CLASS to be compiled locally on the user’s machine. If this compilation fails, users can edit the default configuration variables in depends/class.cfg, which are used when building the CLASS library. If compilation problems persist, try using the Anaconda installation method.

Verifying the Installation

To verify that the installation has succeeded, run:

import classylss