Object-Oriented Python

Site Admin · 11 Sep 2026 · 7 views

Object-Oriented Python

Thinking in Objects

Object-oriented programming (OOP) organizes code around objects: things that combine data (attributes) with behavior (methods). A class is the blueprint, and an object is a concrete instance built from that blueprint. Python supports OOP naturally, and even if you prefer simple scripts, understanding classes helps you read most real-world Python code.

class Dog:
    def __init__(self, name):
        self.name = name

    def bark(self):
        return f"{self.name} says Woof!"

rex = Dog("Rex")
print(rex.bark())    # Rex says Woof!

The __init__ method runs when an object is created and sets up its starting state. The self parameter refers to the current instance, and self.name stores a value on that instance.

Attributes and Methods

Attributes hold data, and methods define behavior. Instance attributes, created by assigning to self inside methods, belong to each object individually. Two Dog objects can therefore hold different names without interfering with each other.

Methods that take self operate on the instance. Static methods, marked with @staticmethod, do not need an instance and behave like plain functions attached to the class. Class methods, marked with @classmethod, receive the class itself and are often used as alternate constructors.

Inheritance

Inheritance lets a class reuse and extend another class. The child class inherits attributes and methods from the parent and can override them with its own versions.

class Animal:
    def speak(self):
        return "..."

class Cat(Animal):
    def speak(self):
        return "Meow"

print(Cat().speak())   # Meow

Encapsulation, the idea of hiding internal details, is kept simple in Python: underscore-prefixed names such as _internal signal that a member is private by convention.

When OOP Helps

OOP shines when you model real entities with both data and behavior, reuse logic through inheritance, or build pluggable systems that share the same interface. For small scripts a few functions may be simpler. Start introducing classes as code grows so that responsibilities become clear.