Grid best viewd in monospaced font

tic-tac-toe.py

# -*- coding: utf-8 -*-

class IllegalMove(Exception):
    pass

class TicTacToe(object):
    player_1_symbol = "O"
    player_2_symbol = "X"
    empty_symbol = " "

    def __init__(self):
        self.board = [ self.empty_symbol, self.empty_symbol,
                       self.empty_symbol, self.empty_symbol,
                       self.empty_symbol, self.empty_symbol,
                       self.empty_symbol, self.empty_symbol,
                       self.empty_symbol, ]
        self.current_player = self.player_1_symbol


    @property
    def has_ended(self):
        return self.empty_symbol not in self.board

    @property
    def has_winner(self):
        return (self.player_has_won(self.player_1_symbol) or
                self.player_has_won(self.player_2_symbol))


    @property
    def has_tied(self):
        return self.has_ended and not self.has_winner


    @property
    def winner(self):
        if self.player_has_won(self.player_1_symbol):
            return self.player_1_symbol
        elif self.player_has_won(self.player_2_symbol):
            return self.player_2_symbol
        else:
            return None


    def move(self, position):
        if self.is_square_empty(position):
            self.board[self.translate_move(position)] = self.current_player

            if self.current_player == self.player_1_symbol:
                self.current_player = self.player_2_symbol
            else:
                self.current_player = self.player_1_symbol
        else:
            raise IllegalMove

    def is_square_empty(self, position):
        return self.board[self.translate_move(position)] == self.empty_symbol

    def player_has_won(self, symbol):
        if (self.board[0] == symbol and
            self.board[1] == symbol and
            self.board[2] == symbol):
            return True
        elif (self.board[3] == symbol and
              self.board[4] == symbol and
              self.board[5] == symbol):
            return True
        elif (self.board[6] == symbol and
              self.board[7] == symbol and
              self.board[8] == symbol):
            return True
        elif (self.board[0] == symbol and
              self.board[3] == symbol and
              self.board[6] == symbol):
            return True
        elif (self.board[1] == symbol and
              self.board[4] == symbol and
              self.board[7] == symbol):
            return True
        elif (self.board[2] == symbol and
              self.board[5] == symbol and
              self.board[8] == symbol):
            return True
        elif (self.board[0] == symbol and
              self.board[4] == symbol and
              self.board[8] == symbol):
            return True
        elif (self.board[2] == symbol and
              self.board[4] == symbol and
              self.board[6] == symbol):
            return True
        else:
            return False

    def translate_move(self, position):
        if position == "TL":
            return 0
        elif position == "TC":
            return 1
        elif position ==  "TR":
            return 2
        elif position == "ML":
            return 3
        elif position ==  "MC":
            return 4
        elif position ==  "MR":
            return 5
        elif position == "BL":
            return 6
        elif position == "BC":
            return 7
        elif position == "BR":
            return 8



    def __repr__(self):
        return " {0} | {1} | {2} \n———————\n {3} | {4} | {5} \n———————\n {6} | {7} | {8} \n".format(self.board[0], self.board[1], self.board[2], self.board[3], self.board[4], self.board[5], self.board[6], self.board[7], self.board[8], )


if __name__ == "__main__":
    game = TicTacToe()
    while not game.has_ended:
        print game
        print "{0}'s turn".format(game.current_player)
        move = raw_input("Input Move: Top Left (TL), Top Center (TC), Top "
                          "Right (TR), Middle Left (ML), Middle Center (MC), "
                          "Middle Right (MR), Bottom Left (BL), Bottom Center "
                          "(BC), Bottom Right (BR)")
        if move not in ("TL", "TC", "TR", "ML", "MC", "MR", "BL", "BC", "BR"):
            print "Invalid Input"
            continue

        try:
            game.move(move)
        except IllegalMove:
            print "Illegal Move {0}. Try Again".format(move)
            continue

        if game.has_winner:
            print "{0} Wins!!! Congrats!".format(game.winner)
            break

    print game
    if game.has_tied:
        print "No Winner. Maybe next time."