Introduction to Classes and Objects

Thinking in Objects

Until now, we’ve focused on Procedural Programming—writing a list of instructions for the computer to follow. As programs grow, it becomes easier to organize code around “things” (Objects) rather than just “actions”.

Object-Oriented Programming (OOP) allows us to group data (attributes) and functionality (methods) together into a single unit called an Object.

Classes vs. Objects

Think of a Class as a blueprint or a recipe. It describes what something is and what it can do. An Object is an actual instance created from that blueprint.

• Class: Dog (The concept)
• Object: Your pet “Rex” (The real dog)

Defining a Class

In Python, we use the class keyword.

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class Dog:
    pass # Empty class for now

# Creating an object (instantiating)
my_dog = Dog()
print(my_dog)

Attributes (Data)

Objects can store data. These are called Attributes. We can assign them directly to an object.

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class Dog:
    pass

rex = Dog()
rex.name = "Rex"
rex.breed = "German Shepherd"

print(f"My dog's name is {rex.name}")

Methods (Behavior)

Functions defined inside a class are called Methods. They define what the object can do.

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class Dog:
    def bark(self):
        print("Woof! Woof!")

rex = Dog()
rex.bark()

What is self?

Notice the self parameter in the method. self refers to the specific instance of the object that is calling the method. It allows the function to access that object’s own data.

Interactive Practice

Imagine you are building a game. You might have a Player class. What attributes (like health or name) and methods (like jump or attack) would it have?