The Ghent Quantum Chemistry Package (GQCP) aims to provide an open-source domain specific language (DSL) for general electronic structure method development in spinor bases. This DSL is implemented in a C++ library with Python bindings.
GQCConstraints (or GQCC for short) is a python extension built for GQCP. It provides the necessary methods and classes to run constrained calculations for several quantum chemical ansatzes. In order to use the extension, download the GQCP docker container and in it, simply run
pip install GQCConstraints