Core Object Oriented Principles

Object Oriented Programming is built on four core principles that work together to make code organized, reusable, and easier to maintain: Encapsulation, Abstraction, Inheritance, and Polymorphism.

Encapsulation

Encapsulation means bundling data and the methods that operate on that data together within a single class, while restricting direct access to some of the object's internal details (as seen earlier with private attributes).

Abstraction

Abstraction means exposing only the essential features of an object while hiding the complex implementation details behind the scenes. When you call list.sort(), you don't need to know exactly how the sorting algorithm works internally - you just use the simple interface it provides.

Inheritance

Inheritance allows a new class to reuse the attributes and methods of an existing class, extending or customizing them as needed, rather than rewriting everything from scratch. This is covered in full detail in the next topic.

Polymorphism

Polymorphism means the same method name can behave differently depending on which object calls it.

class Dog:
    def speak(self):
        return "Woof!"

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

for animal in [Dog(), Cat()]:
    print(animal.speak())

Both classes have a speak() method, but calling it produces a different result depending on the actual object - that's polymorphism in action.

Together, these four principles are what separate true Object Oriented design from simply organizing code into classes - understanding all four deeply is what lets you design genuinely maintainable, scalable software.

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