Yuppy is a small Python library that integrates seamlessly with your application to promote data integrity by supporting common object-oriented language features. It intends to provide fully integrated support for interfaces, abstract classes and methods, final classes and methods, and type hinting in a manner that preserves much of the dynamic nature of Python. Yuppy can improve the integrity of your data and the stability of your code without comprimising usability. It is easy to use and is intentionally designed to fit with the Python development culture, not circumvent it.