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Deepest Dungeon - Python OOP

A cartoon adventurer with a torch exploring a dungeon

This site guides us through the fundamentals of object-oriented programming (OOP) in Python by building a text-based adventure game. Each stage adds a new feature to the dungeon, and shows how classes, objects, methods and inheritance fit together in a real program. We use Thonny to write and run our code.

How to use this site

  • Start with the Introduction for Students to set up Thonny and your project folder, then read the OOP Primer.
  • Work through the stages in order, starting with Stage 1: Create Rooms, at your own pace. If you finish early, try the Extensions.
  • Your teacher will live code each stage in class. That's the minimum progress to aim for. If you fall behind, use this site to catch up.
  • Each stage uses PRIMM: we predict what code will do, run it, investigate how it works, modify it, and finally make our own features in the exercises.

Callouts

Coloured boxes called callouts highlight different kinds of information. Each type of callout has its own colour and icon, so we can tell at a glance what it's for.

Learning intentions

This callout is at the top of every stage. It lists what we will learn in that stage.

Terminology

This callout comes straight after the learning intentions. It lists the new technical terms on the stage, with a short definition of each. Every term is also on the Glossary page.

PRIMM

This callout comes after each example program. It asks us to predict what the code will do, run it, and investigate how it works. Sometimes it asks us to modify the code.

Code explanation

This callout comes after each PRIMM callout and gives a line-by-line explanation of the new code. On the stage pages it starts closed, so we can make our own prediction first. Click its title to open it.

Tip

This callout gives extra information, such as definitions, background facts, comparisons and hints.

Warning

This callout warns us about mistakes that are easy to make, or things that will stop our program working.

Code blocks

Programs are shown in code blocks like this one:

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# main.py

print("Welcome to the Deepest Dungeon")
  • The first line is a comment with the file name, because our game is split across several files.
  • The line numbers on the left match the line numbers used in the Code explanation and in error messages.
  • Highlighted lines show the lines that are new or have changed since the last version of the file. Only these lines are explained in the Code explanation.
  • The copy button in the top-right corner of a code block copies the code, so we can paste it into Thonny.

Code blocks without colours show what appears in the Shell when we run a program, or the pseudocode that plans a stage.

Error messages

Error messages are shown in red code blocks like this one:

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Traceback (most recent call last):
  File "main.py", line 3, in <module>
NameError: name 'prnt' is not defined

Under each error message, the stage breaks it down line by line, so we learn how to read the error and fix our code.

Tutorial files

Download the tutorial files. The zip has a folder for each stage and extension, containing the finished code for that stage.

If you fall behind or your code stops working, you can pick up from a checkpoint:

  1. Download and unzip the file into your own folder.
  2. Copy the files from the folder of the last stage you finished into your deepest_dungeon folder.
  3. Open main.py in Thonny (File → Open) and start the next stage.