Free lab Real Python 3. Zero installs. Your code stays in this browser. Open the playground

Functions & OOP

Functions turn repeated code into reusable building blocks; classes model the real world. This is where you stop writing scripts and start engineering software.

Intermediate 6 lessons 200 XP ~94 min
Real work, not toy syntax

What this course helps you build

Each lesson connects the Python concept to work you could automate, analyse or ship.

Delivery pricing engine

Package reusable pricing rules into small, testable functions.

Bank account model

Keep balances and deposit or withdrawal behaviour together in a class.

Reusable validators

Build functions that check emails, form fields and imported records.

Game characters

Use inheritance and objects for players with different abilities.

Course roadmap

  1. 1

    Defining Functions Start here

    14 min 25 XP 2 quiz 1 challenge
    Start →
  2. 2

    Default, Keyword, *args & **kwargs

    15 min 30 XP 2 quiz 1 challenge
    Start →
  3. 3

    Scope, Lambda & Higher-Order Functions

    14 min 30 XP 2 quiz 1 challenge
    Start →
  4. 4

    Classes & Objects

    18 min 35 XP 2 quiz 1 challenge
    Start →
  5. 5

    Inheritance & super()

    15 min 35 XP 1 quiz 1 challenge
    Start →
  6. 6

    Mini Project: Playing Cards with Dunders

    18 min 45 XP 1 quiz 1 challenge
    Start →

You can take every lesson without an account — but create a free account to save progress, earn XP and unlock achievements.

Your next ten minutes

Write Python that does something useful.

Start free. No install, no card, no passive video marathon.

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