Descriptors and Controlled Attributes in Python

In this article, you will learn what Python descriptors are and how to use them to build three types of controlled attributes: validated, computed, and lazily loaded. How to build a validated attribute descriptor that enforces type and range constraints on class attributes. How to build a computed attribute descriptor that derives its value dynamically from another attribute. How to build a lazily loaded attribute descriptor that defers expensive computations until the attribute is first accessed. In Python, descriptors are a mechanism that governs what occurs when we access an object’s attribute, set it, or remove it. They are defined through a powerful protocol whereby a class implements special methods like __get__, __set__, and so on, to customize access to the attribute(s). Meanwhile, controlled attributes are properties…