trainstation is a tool that allows the efficient construction of linear models. It provides supplementary functionality for handling data and model metrics and relies on the scikit-learn library for the actual training. trainstation has been originally developed to aid the construction of force constant (via hiphive) andcluster expansions (via icet). Since it has proven to be valuable in more general contexts and to simplify the maintenance of the two aforementioned packages, the functionality has been moved into a separate package.