Finite element (FE) model updating in Python by an example. The framework of sensitivity-based FE model updating is implemented in Python and validated through a simple numerical case study utilizing the FE model program Abaqus. FE model updating is performed by considering a simply supported beam. The files include: Implementation of the theoretical framework of sensitivity-based FE model updating by perturbation analysis. Demonstration of an analysis framework, or workflow setup, utilizing the numerical FE model program Abaqus. Description of a numerical case study including results for validation. Experience with Abaqus and Abaqus scripting is not needed, but preferable, for an increased understanding of the numerical case study implementation. The workflow setup is general and the theoretical framework of the model updating can be utilized with other FEM programs by simple modifications to the provided files. The easiest way to get into the use and understanding is to download and run the example files (01_run.py and 02_run_pp.py). The analysis framework is established using Python version 3.7.2, including Scipy version 1.3.2. The numerical FE model is established in Abaqus/CAE release 2017.