A python code to make ellipsometric and spectrophotometric models. It models a stack of isotropic or anisotropic layers on a substrate using Berreman's formalism. This code also include Muller matrix calculations, backside reflection effects on psi and delta ellipsomteric angles, Lorentz oscillator model, Tauc-Lorentz oscillator, classic and anisotropic Bruggeman model, Euler transformation of anisotropic dielectric matrix.