RockPaperScissors

Rock Paper Scissors is a tiny game where you can beat the opponent by countering his rock with paper, his scissors with rock, and his paper with scissors.

You can view or download the code here:

https://github.com/pythonbyexample/PBE/tree/master/code/rockpaper.py

To run RockPaperScissors, you will also need to download ‘utils.py’:

https://github.com/pythonbyexample/PBE/tree/master/code/utils.py

Code

The main logic of the game happens in the run() method: I need to create the textinput instance with a pattern that accepts ‘r’, ‘p’, and ‘s’ inputs and the scores list.

In the main loop, I’m getting the choices (inputs) of each player; if they are the same, I don’t need to do anything because it’s a draw. If they’re not the same, I check if combined choices are in wins tuple – if they are, the 2nd player wins, otherwise the 1st player wins – corresponding to the 1st and 0th indexes in the scores list, which I then increment.

Finally, I print out the status message with updated scores and moves and then pause for a short time (the only reason I do that is to slow things down when AI plays vs. AI).

wins = ("rp", "sr", "ps")   # choice on the right side wins

class RockPaperScissors(object):
    def run(self):
        self.textinput = TextInput("(r|p|s)")
        scores         = [0, 0]

        while True:
            choice1, choice2 = (self.get_move(p) for p in players)

            if choice1 != choice2:
                winplayer = 1 if (choice1+choice2 in wins) else 0
                scores[winplayer] += 1

            print(status % (players[0], scores[0], players[1], scores[1], choice1, choice2))
            sleep(pause_time)

In the get_move() function, I only need to check if the player is AI and return a random move or the player’s move from textinput.

You can quit the game by using the ‘q’ key.

def get_move(self, player):
    if player in ai_players : return randchoice(moves)
    else                    : return self.textinput.getval()

Configuration

You can run the game in AI vs. AI mode, play against the AI, or play against human by setting the ai_players accordingly.

players    = "XY"
ai_players = "Y"

Screenshots

A sample run, I’m playing ‘X’:

> r
X   0     Y   0     moves: r r
> r
X   1     Y   0     moves: r s
> r
X   1     Y   0     moves: r r
> r
X   1     Y   1     moves: r p
> r
X   1     Y   2     moves: r p
> r
X   1     Y   2     moves: r r
> r
X   2     Y   2     moves: r s
> p
X   3     Y   2     moves: p r
> p
X   3     Y   3     moves: p s
> s
X   4     Y   3     moves: s p
> s
X   4     Y   4     moves: s r