Python 3 Deep Dive Part 4 Oop | [updated]

Hiding complex implementation details and showing only the necessary features of an object. 2. Classes and Instances: The Anatomy of Objects

class PositiveInteger: def __init__(self, name): self.name = name def __get__(self, instance, owner): if instance is None: return self return instance.__dict__.get(self.name) def __set__(self, instance, value): if not isinstance(value, int) or value < 0: raise ValueError(f"self.name must be a positive integer.") instance.__dict__[self.name] = value class Product: # Descriptors must be defined at the class level price = PositiveInteger('price') def __init__(self, name, price): self.name = name self.price = price Use code with caution.

class Book: def __init__(self, title, author, year): self.title = title self.author = author self.year = year self.checked_out = False

print(issubclass(Rectangle, Drawable)) # True python 3 deep dive part 4 oop

class BankAccount: def __init__(self, balance): self.__balance = balance

In Python, classes are objects; they are instances of a . The default metaclass is type , but you can create your own to intercept the creation of a class.

from abc import ABC, abstractmethod

ABCs define interfaces and enable .

@property def checked_out(self): return self._checked_out

super() delegates to the next class in the MRO , not necessarily the parent. It enables cooperative multiple inheritance. Hiding complex implementation details and showing only the

: Detailed coverage of "dunder" methods (e.g., __str__ , __repr__ , __del__ ) and how they enable custom behavior for arithmetic operators and rich comparisons.

Reviews from platforms like CourseDuck and Udemy consistently highlight the course's depth, noting that it provides a vocabulary for discussing code architecture that isn't found in "cookbook-style" tutorials. It is widely regarded as a definitive resource for transitioning from "knowing Python" to understanding its internal engineering. Python 3: Deep Dive (Part 4 - OOP) - Udemy

To wrap traditional attributes with logic without breaking public interfaces, Python provides @property . The default metaclass is type , but you

print(type(foo)) # <class 'function'> print(type(type)) # <class 'type'> print(type(int)) # <class 'type'>

End of Report – Python 3 Deep Dive Part 4: OOP