Classes

What is object-oriented programming?

Object-oriented programming (OOP) is a way to organize code by grouping related data and functions together. Instead of having separate variables and functions scattered around, you bundle them into objects. Think of it like organizing a toolbox:

Without OOP: Tools scattered everywhere
With OOP: Tools organized in labeled compartments

Classes are a more advanced Python concept. Don’t worry if they feel confusing at first - they’ll click with practice. Many Python programs work perfectly fine without classes, but they become valuable as your projects grow.

What is a class?

A class is a blueprint for creating objects. It defines:

Attributes: What data the object stores
Methods: What the object can do

# Without classes - data and functions separate
name = "OpenAI"
model = "gpt-4o-mini"

def generate_response(prompt):
    # Process prompt...
    return response

# With classes - everything bundled together
class OpenAIClient:
    def __init__(self, name, model):
        self.name = name
        self.model = model
    
    def generate_response(self, prompt):
        # Process prompt...
        return response

Why use classes?

Classes help you write more understandable programs as they grow. Here’s the typical progression of a Python developer: 1. Single file scripts (where you started):

# everything.py - All code in one file
api_key = "sk-..."
prompt = "Explain Python"
response = make_api_call(api_key, prompt)
print(response)

2. Functions (where you are now):

# main.py - Organized with functions
def setup_api(key):
    return {"key": key, "base_url": "https://api.openai.com"}

def generate_response(api_config, prompt):
    # Make API call
    return response

api = setup_api("sk-...")
result = generate_response(api, "Explain Python")

3. Multiple files (getting organized):

# api_utils.py
def setup_api(key):
    return {"key": key, "base_url": "https://api.openai.com"}

# main.py
from api_utils import setup_api
api = setup_api("sk-...")

4. Classes (where we are now):

# client.py
class OpenAIClient:
    def __init__(self, api_key):
        self.api_key = api_key
        self.base_url = "https://api.openai.com"
    
    def generate(self, prompt):
        # All logic encapsulated here
        return response

# main.py
from client import OpenAIClient
client = OpenAIClient("sk-...")
response = client.generate("Explain Python")

In the context of AI, classes specifically help you:

Build clean interfaces to APIs
Manage complex data pipelines
Create reusable components
Organize stateful operations

Your first class

Create a simple class

Methods and attributes

Add functionality to classes

Inheritance

Build on existing classes

When to use classes

Best practices and guidelines

Functions

External tools

Practical Python

Error handling

Classes

What is object-oriented programming?

What is a class?

Why use classes?

Your first class

Methods and attributes

Inheritance

When to use classes

​What is object-oriented programming?

​What is a class?

​Why use classes?

Your first class

Methods and attributes

Inheritance

When to use classes

What is object-oriented programming?

What is a class?

Why use classes?