Build Tic Tac Toe

tic_tac_toe.py

import copy

BOARD_FORMAT = '{} | {} | {}\n-----------\n{} | {} | {}\n-----------\n{} | {} | {}\n-----------\n'

class TicTacToe:
    def __init__(self):
        self.board = [[None, None, None], [None, None, None], [None, None, None]]
        self.cur_turn = 'X'
        
    def __repr__(self):
        printable_board = copy.deepcopy(self.board[0])
        printable_board.extend(self.board[1])
        printable_board.extend(self.board[2])
        
        formatted_board = ['-' if x is None else x for x in printable_board]
        
        return BOARD_FORMAT.format(*formatted_board)
    
    def play(self, x, y):
        if self.get_game_winner() is not None:
            raise Exception('Cannot play because game has ended')
            
        if x < 0 or x > 2 or y < 0 or y > 2:
            raise Exception('Invalid coordinates given')
        
        if self.board[x][y] is not None:
            raise Exception('This position has already been played')
            
        self.board[x][y] = self.whose_turn_is_it()
        self.change_turn()
    
    def change_turn(self):
        if self.cur_turn == 'X':
            self.cur_turn = 'O'
        else:
            self.cur_turn = 'X'
    
    def whose_turn_is_it(self):
        return self.cur_turn
    
    def get_game_winner(self):
        # Horiztonal win condition
        if self.board[0][0] == self.board[0][1] and self.board[0][1] == self.board[0][2]:
            if self.board[0][0] is not None:
                return self.board[0][0]
        if self.board[1][0] == self.board[1][1] and self.board[1][1] == self.board[1][2]:
            if self.board[1][0] is not None:
                return self.board[1][0]
        if self.board[2][0] == self.board[2][1] and self.board[2][1] == self.board[2][2]:
            if self.board[2][0] is not None:
                return self.board[2][0]
        
        # Vertical win condition
        if self.board[0][0] == self.board[1][0] and self.board[1][0] == self.board[2][0]:
            if self.board[0][0] is not None:
                return self.board[0][0]
        if self.board[0][1] == self.board[1][1] and self.board[1][1] == self.board[2][1]:
            if self.board[0][1] is not None:
                return self.board[0][1]
        if self.board[0][2] == self.board[1][2] and self.board[1][2] == self.board[2][2]:
            if self.board[0][2] is not None:
                return self.board[0][2]
            
        if self.board[0][0] == self.board[1][1] and self.board[1][1] == self.board[2][2]:
            if self.board[0][0] is not None:
                return self.board[0][0]
        if self.board[0][2] == self.board[1][1] and self.board[1][1] == self.board[2][0]:
            if self.board[0][2] is not None:
                return self.board[0][2]
        
        return None
    
    def has_game_ended(self):
        if self.get_game_winner() is not None:
            return True
        
        for row in self.board:
            if None in row:
                return False
            
        return True
    
    def reset(self):
        self.board = [[None, None, None], [None, None, None], [None, None, None]]
        
def main():
    game = TicTacToe()
    
    while (not game.has_game_ended()):
        print(game)
        
        print('It\'s {}\'s turn'.format(game.whose_turn_is_it()))
        
        try:
            x = input('Please enter x co-ordinate of the position you want to play: ')
            y = input('Please enter y co-ordinate of the position you want to play: ')
            game.play(int(x), int(y))
        except Exception as e:
            print('ERROR: {}'.format(str(e)))
            continue
        
    winner = game.get_game_winner()
    if winner is None:
        print('Game ended in stalemate')
    else:
        print('{} won the game!'.format(winner))
        
    game.reset()
    

main()
        
# t = TicTacToe()
# print(t)
# t.play(0,0)
# print(t)
# t.play(1,0)
# print(t)

# t.play(2,0)
# print(t)
# t.play(1,1)
# print(t)

# t.play(0,2)
# print(t)
# # t.play(1,2)
# # print(t)
# # print(t.get_game_winner())

# t.play(2,2)
# print(t)

# t.play(2,1)
# print(t)
# t.play(0,1)
# print(t)

# t.play(1,2)
# print(t)

# print(t.get_game_winner())
# print(t.has_game_ended())

# t.play(0,0)
# t.play(3, 3)