Blackjack is a casino game involving just a deck of cards. The aim of the game is to get as close as possible to a hand worth 21 points – but go over and you're out!

Number cards are worth their face value, picture cards are worth 10, and an ace is worth either 1 or 11 depending on your other cards. Players are initially dealt two cards and can either choose to hit (receive another card) or stick (submit their current hand).

Players face off against the dealer, who has one card face down and one face up. When all players have chosen to stick or are out (having a hand over 21), the winner is the one with a hand closest to 21.

Why am I telling you about blackjack? Because we're going to make a blackjack game using Tkinter! Not only will this chapter introduce you to powerful widgets, such as the canvas and Frame widgets, but it will also teach something that I come across a lot in the world of GUI programming—having a CLI program and the desire to make it a GUI, but not knowing how.

We will begin with a simple CLI version of blackjack that is playable, then build the interface around it, keeping the core functionality and logic the same.

Within this chapter, we will cover the following topics:

• What a class is and how to create one in Python
• How inheritance works
• How to apply polymorphism
• Using classes to model aspects of blackjack
• Creating and exiting a game loop

Before we begin coding our blackjack game, it's important we clear up how object-oriented programming works, since we will need to utilize classes even for the command-line version of our game.