In this paper, we present an alternative for driving Sonnet’s 3D planar electromagnetic simulator from Python. Such a driver facilitates parameter sweeps and optimization with Sonnet. In general, the proposed Python driver enables users to control and automate many functionalities of Sonnet’s EM simulator. The main advantage of using Python is that it is free to use and distribute, in contrast to other solutions such as Matlab, which requires the user to have a license. For a user who is working with Sonnet Lite, which can also be obtained for free (registration required), a Python-based interface increases the flexibility of parameterization at no financial cost, which can be an excellent alternative for educational purposes.ITESO, A.C.