Python 3 Deep Dive Part 4 Oop -

def __set__(self, obj, value): if not isinstance(value, (int, float)): raise TypeError(f"self._name must be a number") if value <= 0: raise ValueError(f"self._name must be positive") obj.__dict__[self._name] = value

As with all powerful tools, wisdom lies in knowing when to use them. Metaclasses and descriptors should be deployed sparingly, with careful documentation. __slots__ is a targeted optimization for memory-intensive workloads. Abstract base classes provide clarity and runtime safety without sacrificing flexibility.

By omitting a setter, you can create read-only properties. This is useful for properties that depend on other attributes (e.g., area depends on radius ). 3. Advanced Attribute Management __getattr__ and __getattribute__ python 3 deep dive part 4 oop

A mixin is a small class that provides specific behavior but is not meant to stand alone.

reduce boilerplate while maintaining readability. Abstract base classes provide clarity and runtime safety

Inheritance is one of the four main OOP principles (along with encapsulation, polymorphism, and abstraction). Method Resolution Order (MRO)

e = Example() print(Example.instance_method) # <function Example.instance_method at ...> print(e.instance_method) # <bound method Example.instance_method of <...>> function Example.instance_method at ...&gt

def perimeter(self): return 2 * (self.width + self.height)

You can access the attributes and methods of the object using dot notation, like this:

def area(self): return 3.14 * self.radius ** 2