tictactoe_comp.py

# Written by: Ryan Yan
# Paired with Oskar Thoren
# Date: October 11th, 2016
#
# This program lets you play tic tac toe in the console using keyboard input against a computer.
import random

class Player:
    '''Player objects keep track of the spaces they control on the grid (add_square and get_squares)
    and has their symbol, default X's and O's as their string representation'''

    def __init__(self, symbol, human = True):
        self._squares = set() #Set of controlled spaces. Holds indices from 0-8 held by player in Board._grid
        self._symbol = symbol
        self._human = human
    def add_square(self, ind):
        self._squares.add(ind)
    def get_squares(self):
        return self._squares.copy()
    def is_Human(self):
        return self._human
    def __str__(self):
        return self._symbol


class Board:
    '''Tictactoe game class. Contains the grid to be printed, a list of available spaces, and makes moves
    occur and determines the victor.'''

    def __init__(self):
        self._grid = list(range(1, 10, 1)) #Grid to be printed. filled with X and Os
        self._squares = list(range(9)) #List of available spaces. Holds indices from 0-8 open in _grid
        self._win_conditions = [{0,1,2}, {3,4,5}, {6,7,8}, #rows
                                {0,3,6}, {1,4,7}, {2,5,8}, #columns
                                {0,4,8}, {2,4,6}]          #diagonals
        self._victor = None

    def clear_grid(self):
        self._grid = [""] * 9

    def make_move(self, player):
        if not self._squares: #If no spaces are left, but someone has to move, then it was a tie
            self._victor = "Nobody"

        if player.is_Human():
            #Asks for input and updates all the square lists in Player and in Board, then checks win condition
            while(True):
                #Checks and validates input
                try:
                    move = int(input("%s's move: " % str(player))) - 1
                    self._squares.index(move)
                    break
                except ValueError:
                    print("Please enter an integer between 1 and 9")
        else:
            move = self.computer_move(player)

        #Updates lists containing squares and checks victory conditions.
        self._squares.remove(move)
        player.add_square(move)
        self._grid[move] = str(player)
        self.check_win(player)

    def computer_move(self, player):
        #The computer checks if any moves will result in victory, and does that. Failing this, it picks
        #a random square.
        for square in self._squares:
            for condition in self._win_conditions:
                combined = player.get_squares()
                combined.add(square)
                if condition.issubset(combined):
                    return square;

        chosen = random.randint(0, len(self._squares) - 1)
        move = self._squares[chosen]
        return move


    def check_win(self, player):
        #Checks if any victorious set of squares is a subset of squares held by a particular player
        held_squares = player.get_squares()
        for condition in self._win_conditions:
            if condition.issubset(held_squares):
                self._victor = player
                return

    def play(self):
        #Sets up the game
        player_one = Player("X")
        player_two = Player("O", False)
        players = [player_one, player_two]
        current_player = 0
        print(self)
        self.clear_grid()
        print("Use integers 1-9 to specify the location on the board")

        #Gameplay
        while(self._victor == None):
            self.make_move(players[current_player%2])
            print(self)
            current_player = current_player + 1

        print("The %s's have it!" % str(self._victor))

    def __str__(self):
        #Prints out the game board
        for row in range(3):
            adjust = 3 * row
            print("%2s%2s%2s%2s%2s" % (self._grid[adjust+0], "|", self._grid[adjust+1], "|", self._grid[adjust+2]))
            if(row != 2):
                print("___|___|___")
            else:
                print("%4s%4s" % ("|", "|"))

        return ""

if __name__ == "__main__":
    new_game = Board()
    new_game.play()