C2C: Setup and Face-up Poker

Set up your environment

You can use a code editor of your choice. We like VSCode. You can also work with Google Colab in the browser. The instructions below are for coding locally on MacOS or Unix.

Step 1: Make directory

Make a local directory for the project cardstocode. From the command line:

mkdir cardstocode
cd cardstocode

Step 2: Virtual environment

Create and activate a virtual environment:

python3 -m venv venv
source venv/bin/activate

You should now see (venv) at the beginning of your command prompt, indicating that the virtual environment is active.

Step 3: Create Python file

Create a Python file c2c.py. From the command line:

touch c2c.py

Step 4: Deactivating and reactivating virtual environment

To deactivate:

deactivate

To reactivate:

source venv/bin/activate

Step 5: Install numpy

Install numpy, which we will use later.

pip install numpy

Face-up 1-card poker

We’ll start by setting up a poker game with a 3-card deck where the cards are given values {0, 1, 2}. Each player is dealt a card “face-up” and the higher card wins. This is like the game War, but even more simplified because there are no ties since the entire deck is only 3 cards.

Step 1: Imports

Let’s start by importing numpy (will be used later) and random.

Imports

import numpy as np
import random

Step 2: Cards and scores

Define a Game class that is initialized with these class attributes:

• 3-card deck array with cards 0, 1, and 2

• Card placeholders for each player in a cards array that are initialized as None

• Score placeholders for each player in scores array that are initialized as 0

Initialize Game class

class Game:
    def __init__(self):
        self.deck = [0, 1, 2]
        self.cards = [None, None]
        self.scores = [0, 0]

Step 3: Deal cards

Let’s now add a deal_cards function into the Game class that samples two cards from the deck into self.cards. This is the first of two class methods.

deal_cards function

    def deal_cards(self):
        self.cards = random.sample(self.deck, 2)

Step 4: Compare cards

Accumulate the scores for each player using self.scores in a compare_cards function. This is the second class method.

play_round function

    def compare_cards(self):
        if self.cards[0] > self.cards[1]:
            self.scores[0] += 1
            self.scores[1] -= 1
        elif self.cards[0] < self.cards[1]:
            self.scores[0] -= 1
            self.scores[1] += 1

Step 5: Play round

Create a play_round function in the Game class that deals the cards using self.deal_cards.

Update play_round function

    def play_round(self):
        self.deal_cards()
        self.compare_cards()

Step 6: Run the game

Create the main function that defines num_games as 100, creates an object of the Game class in game, and runs the game num_games times.

main function

def main():
    num_games = 100
    game = Game()

    for _ in range(num_games):
        game.play_round()

The game object now has all the attributes and methods defined in the Game class.

Step 7: Print the scores

Print the scores for each player after the game ends, also in the main function.

Print scores

    print(f"After {num_games} games:")
    print(f"Player 1 score: {game.scores[0]}")
    print(f"Player 2 score: {game.scores[1]}")

Step 8: Create the main block

Main block

if __name__ == "__main__":
    main()

Putting it all together

All the code

import random

class Game:
    def __init__(self):
        self.deck = [0, 1, 2]
        self.cards = [None, None]
        self.scores = [0, 0]

    def deal_cards(self):
        self.cards = random.sample(self.deck, 2)

    def compare_cards(self): 
        if self.cards[0] > self.cards[1]:
            self.scores[0] += 1
            self.scores[1] -= 1
        elif self.cards[0] < self.cards[1]:
            self.scores[0] -= 1
            self.scores[1] += 1

    def play_round(self):
        self.deal_cards()
        self.compare_cards()

def main():
    num_games = 100
    game = Game()

    for _ in range(num_games):
        game.play_round()

    print(f"After {num_games} games:")
    print(f"Player 1 score: {game.scores[0]}")
    print(f"Player 2 score: {game.scores[1]}")

if __name__ == "__main__":
    main()

Run the code

python3 c2c.py

The output should look something like:

Sample code output from 100 games

After 100 games:
Player 1 score: -12
Player 2 score: 12