Basic Entity Management System

How can I design an Entity Management system in Django which can be able to adapt to any kind of entity with minimal code changes (e.g. a product in a catalog, patient information in healthcare etc.).

1. Adding, removing, modifying the attributes of an entity should be simple
2. It should allow for nested attributes (sub-entities) e.g Patient -> Consulting doctor
3. Each attribute or sub-entity in the entity can have a set of business rules