RecurseTacToe

recurse_tac_toe.py

# IDEAS FOR COMPUTERIZED OPPONENT:
# [] Add prompt for 1 Player or 2 Player at start of game
# [] Based on number of players, override player selection with random computer selection
# [] Once random selection is working, add more intelligent computer selection (some ideas):
#      * If computer could win game, it should win game
#      * If computer can put board in state where next move it could win game, it should do that move
#      * If computer can put board in state where next move it could win game REGARDLESS of human selection, do that move
#      * Apply deep learning on millions of games of tic tac toe to become the ultimate RecurseTacToe algorithm (just kidding :D)

BOARD_TEMPLATE = '''
 {top_left} | {top_middle} | {top_right} 
-----------
 {middle_left} | {center} | {middle_right} 
-----------
 {bottom_left} | {bottom_middle} | {bottom_right} 
 '''

# Dictionary containing current state of the board
board_state = {
    'top_left':' ',
    'top_middle':' ',
    'top_right':' ',
    'middle_left':' ',
    'center':' ',
    'middle_right':' ',
    'bottom_left':' ',
    'bottom_middle':' ',
    'bottom_right':' ',
}

# Define all the winning combinations
winning_combinations = (
    # left to rights
    ('top_left', 'top_middle', 'top_right'),
    ('middle_left', 'center', 'middle_right'),
    ('bottom_left', 'bottom_middle', 'bottom_right'),
    # top to bottoms
    ('top_left', 'middle_left', 'bottom_left'),
    ('top_middle', 'center', 'bottom_middle'),
    ('top_right', 'middle_right', 'bottom_right'),
    # diagonals
    ('top_left', 'center', 'bottom_right'),
    ('top_right', 'center', 'bottom_left'),
)

def get_player_symbols():
    """Prompt for symbol selection.
    Args:
        None
    
    Returns:
        dict: mapping of player name ('Player 1' or 'Player 2') to symbol ('X' or 'O')
    """
    p1_symbol = None    
    while p1_symbol not in ('X', 'O'):
        p1_symbol = input("Player 1, type your symbol! X's or O's: ").upper()
        if p1_symbol not in ('X', 'O'):
            print("\nInvalid Choice: Please type either X's or O's.")
    
    p2_symbol = 'O' if p1_symbol == 'X' else 'X'
    print("Player 1 selected {}'s! That makes Player 2 {}'s.".format(p1_symbol, p2_symbol))
    player_dict = {'Player 1':p1_symbol, 'Player 2':p2_symbol}
    return player_dict

def get_open_spots():
    """Get the open spaces on the board given current board state.
    Args:
        None
    
    Returns:
        tuple: open space options
    """
    return tuple([k.replace('_', ' ') for k,v in board_state.items() if v == ' '])

def is_game_over():
    """Check if game is over.
    Args:
        None
    
    Returns:
        bool: True if game over, False if game shall continue
    """
    return not bool(len(get_open_spots()))

def won_game():
    """Check if game has a winner.
    Args:
        None
    
    Returns:
        str or None: if winner exists, returns winner name ('Player 1' or 'Player 2')
            else returns None
    """
    for player, symbol in player_dict.items():
        for combination in winning_combinations:
            if (
                board_state[combination[0]] == symbol
                and board_state[combination[1]] == symbol
                and board_state[combination[2]] == symbol
            ):
                return player
    return None

def play_turn(whos_turn):
    """Plays turn of tic tac toe and updates board_state.
    Args:
        whos_turn (str): name of player whos turn it is ('Player 1' or 'Player 2')
    
    Returns:
        None
    """
    available = get_open_spots()

    selection = None
    while selection not in available:

        current_board = BOARD_TEMPLATE.format(**board_state)

        if len(available) == 1:
            print('Last available option is {}!'.format(available[0]))
            selection = available[0]
            break

        selection = input("\n{}'s turn ({}'s). Please type one of the following options:\n\n  * {}\n{}\n{} ({}'s): ".format(
            whos_turn,
            player_dict[whos_turn],
            '\n  * '.join(available),
            current_board,
            whos_turn,
            player_dict[whos_turn])).replace("'","")

        if selection not in available:
            print('Invalid or unavailable selection!')

    board_state[selection.replace(' ', '_')] = player_dict[whos_turn]
    print(BOARD_TEMPLATE.format(**board_state))

    return 'Player 2' if whos_turn == 'Player 1' else 'Player 1'

# Play game via command line
if __name__ == '__main__':
    print('\n%%%%%%%%%%%%%%%%%%%%%%%%%%%')
    print(' Welcome to RecurseTacToe! ')
    print('%%%%%%%%%%%%%%%%%%%%%%%%%%%\n')
    player_dict = get_player_symbols()

    winner = None
    whos_turn = 'Player 1'
    while not is_game_over() and not winner:
        whos_turn = play_turn(whos_turn)
        winner = won_game()
    
    if winner:
        print("{} ({}'s) won! Nice job!".format(winner, player_dict[winner]))
    else:
        print("Tie game!")