4. RPS classes

4.1. Python Game design

This version of the game code uses classes: a Player class and a Game class.

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4.2. Player class

Each player will be set up using the Player class.

e.g. computer = Player('Computer').

The Player class will take the name of the player as the argument.

The __init__ method has the name parameter.

class Player:
    def __init__(self, name):
        self.name = name

The name of the player can be obtained using an instance property.

e.g. computer.name

The Player class has a set_move method to set the player move.

e.g. computer.set_move(random.choice(['scissors', 'paper', 'rock']))

class Player:

    def set_move(self, move):
        self.move = move

The player move can be obtained using the instance property. e.g. computer.move

It is good practice to initialise all the attributes in the __init__ method

so the move attribute is initialised to None before it is set to one of the possible moves.

Full code for the Player class is below.

class Player:
    def __init__(self, name):
        self.name = name
        self.move = None

    def set_move(self, move):
        self.move = move

Test the Player class for the computer Player.

import random


class Player:
    def __init__(self, name):
        self.name = name
        self.move = None

    def set_move(self, move):
        self.move = move

computer = Player('Computer')
computer.set_move(random.choice(['scissors', 'paper', 'rock']))
print(computer.name, 'played:', computer.move)

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4.3. Game class

Each game will be set up using the Game class. e.g. game = Game(human, computer).

The Game class will take the the two players (instances of the Player class) as the arguments.

The __init__ method has the the two players as parameters.

class Game:

    def __init__(self, player1, player2):
        self.player1 = player1
        self.player2 = player2

Each game will be set up using the Game class. e.g. game = Game(human, computer).

The Game class will take the the two players (instances of the Player class) as the arguments.

The __init__ method has the the two players as parameters.

class Game:

    def __init__(self, player1, player2):
        self.player1 = player1
        self.player2 = player2

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4.4. Full code

import random


number_matches = int(input('How many matches would you like to play? '))


class Player:
    def __init__(self, name):
        self.name = name
        self.move = None

    def set_move(self, move):
        self.move = move


class Game:
    win_moves = {'paper': 'rock', 'scissors': 'paper', 'rock': 'scissors'}

    def __init__(self, player1, player2):
        self.player1 = player1
        self.player2 = player2

    def get_match_winner(self):
        if self.player1.move == self.player2.move:
            return None
        if Game.win_moves[self.player1.move] == self.player2.move:
            return self.player1
        else:
            return self.player2


human = Player('Human')
computer = Player('Computer')
for i in range(number_matches):
    computer.set_move(random.choice(['scissors', 'paper', 'rock']))
    human.set_move(input('Type your move: rock, paper or scissors. \n'))
    print(computer.name, 'played:', computer.move)
    print(human.name, 'played:', human.move)

    game = Game(human, computer)
    winner = game.get_match_winner()
    if not winner:
        print('Tie!')
    else:
        print(winner.name, 'won')
print('GAME OVER!')

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Tasks

1. Modify the python code to use R, P or S instead of rock, paper or scissors throughout the code.

2. Add counters so that the total wins, losses and draws is printed after each game in python.

3. Modify the code to ask for a valid move from the use by placing the human move in a while loop and test to see if the move is a list or tuple of valid moves.

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4.5. Microbit version

The Microbit version of the game code, using classes, is below.

from microbit import *
import random


class Player:
    def __init__(self, name):
        self.name = name
        # self.move = None

    def set_move(self, move):
        self.move = move


class Game:
    win_moves = {'P': 'R', 'S': 'P', 'R': 'S'}

    def __init__(self, player1, player2):
        self.player1 = player1
        self.player2 = player2

    def get_match_winner(self):
        if self.player1.move == self.player2.move:
            return None
        if Game.win_moves[self.player1.move] == self.player2.move:
            return self.player1.name
        else:
            return self.player2.name

human = Player('human')
microbit = Player('microbit')

display.scroll('A for R, B for P, AB for S', delay=80)
while True:
    microbit.set_move(random.choice(['R', 'P', 'S']))
    while True:
        # short pause to allow time to hold down 2 buttons
        sleep(300)
        if button_a.is_pressed() and button_b.is_pressed():
            human.set_move('S')
            break
        elif button_a.is_pressed():
            human.set_move('R')
            break
        elif button_b.is_pressed():
            human.set_move('P')
            break

    display.scroll(human.move + ' v ' + microbit.move, delay=60)
    game = Game(human, microbit)
    winner = game.get_match_winner()

    if winner == None:
        display.show('=')
    elif winner == 'human':
        display.show(Image.YES)
    elif winner == 'microbit':
        display.show(Image.NO)
    sleep(500)
    display.clear()

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Tasks

1. Modify the microbit code so that after the first game, arrows to the A button and B button are shown to prompt the user to play another game.

2. Add counters so that the total wins, losses and ties is scrolled after each game. e.g. ‘W3 L2 T4’

3. Use if-else after each game to ask to continue playing by pressing the A button or to exit by pressing the B button.

4. Modify the display of the R, P or S to use custom images instead.