Acceleo is the result of several man-years of R&D started in the French company Obeo. Junction between the OMG MTL standard, its team's experience with industrial code generation and the latest research advances into the M2T field, it offers outstanding advantages : High ability to customize, Interoperability, Easy kick off, and much more!
For more details you can visit the Acceleo website.
An exemple of template generating Python from an Ecore model: The complete project is available here. Note that the generated Python code relies on the Python for Capella APIs.