Descriptors

Python Descriptors: Reusable Attribute Behavior Without Magic

Python properties are useful when one class needs a managed attribute. When the same attribute behavior must be reused across many fields or classes, repeating nearly identical properties becomes harder to maintain. Descriptors provide the protocol underneath properties, bound methods, classmethod, staticmethod, and other familiar Python features. A descriptor is an object stored on a class that can participate in reading, writing, or deleting an attribute. Descriptors are powerful because they integrate with normal dotted access such as obj.width. They are also easy to misuse if you do not understand where descriptor instances live, how values should be stored, and which lookup rules Python applies.