In Python, a class is not just a blueprint; it is an object itself. When you define a class using the class keyword, Python executes the block and creates a type object.

Mastering Python 3 OOP is about moving beyond simple data encapsulation. It is about understanding how Python handles attributes via descriptors, how it optimizes memory via slots, and how it structures hierarchies via MRO. By leveraging these advanced tools, you can write code that is not only more efficient but also more expressive and maintainable.

my_dog.bark() my_dog.wag_tail()

class Order: quantity = PositiveNumber() price = PositiveNumber()

Reviews often describe this part of the series as the "gold standard" for professional Python development.