I thought this was about thin film simulations based on the title :) There is a wonderful transfer matrix method library in Python for reflectometry simulation

I thought this was about thin film simulations based on the title :) There is a wonderful transfer matrix method library in Python for reflectometry simulation too, if that's what you were hoping to find. https://github.com/kitchenknif/PyTMM https://github.com/kitchenknif/PyTMM