Python 3 Deep Dive Part 4 Oop High Quality [hot] (Plus)

: Instead of manual getters and setters (common in Java), Pythonic code uses properties to define read-only, computed, or validated attributes . This allows you to change internal implementation without breaking the public API.

class Positive(Validator): def validate(self, value): if value <= 0: raise ValueError(f"self.name must be positive")

class PositiveInt(int): def (cls, value): if value <= 0: raise ValueError("PositiveInt must be > 0") return super(). new (cls, value) python 3 deep dive part 4 oop high quality

class Point3D: __slots__ = ('x', 'y', 'z') def __init__(self, x, y, z): self.x = x self.y = y self.z = z

class Model: def (cls, **kwargs): super(). init_subclass (**kwargs) if not hasattr(cls, ' slots '): cls. slots = tuple() : Instead of manual getters and setters (common

In Python, everything is an object, including classes themselves.

: A strong hint to developers that the attribute is intended for internal use. It is not enforced by the interpreter. new (cls, value) class Point3D: __slots__ = ('x',

Since Python 3.5+, typing and Protocol (PEP 544) bring static duck-typing to OOP.

Now process works with any object having a .read() method — like open() files or custom classes — without inheritance.

class A: def greet(self): print("A")

class NonEmptyString(Validator): def validate(self, value): if not isinstance(value, str) or len(value.strip()) == 0: raise ValueError(f"self.name must be non-empty string")