tictactoe_oop.py

# Tic Tac Toe

TL, TM, TR, ML, MM, MR, BL, BM, BR = 'TL', 'TM', 'TR', 'ML', 'MM', 'MR', 'BL', 'BM', 'BR'
ALL_SPACES = (TL, TM, TR, ML, MM, MR, BL, BM, BR)
X, O, BLANK = 'X', 'O', ' '

def main():
    game = TicTacToeGame()
    game.run()

class TicTacToeGame:
    def run(self):
        print('Welcome to Tic Tac Toe!')
        mainBoard = TicTacToeBoard()
        turn = X
        nextTurn = O

        while True:
            print('It is ' + turn + '\'s turn.')
            mainBoard.drawBoard()
            move = mainBoard.getPlayerMove()
            mainBoard.setSpace(move, turn)

            if mainBoard.isWinner(turn):
                mainBoard.drawBoard()
                print(turn + ' has won the game!')
                break
            elif mainBoard.isFull():
                mainBoard.draw()
                print('The game is a tie!')
                break
            print()

            turn, nextTurn = nextTurn, turn

class TicTacToeBoard:
    def __init__(self, startingMarks=None):
        # Create a new, blank tic tac toe board.
        if startingMarks is None:
            startingMarks = {}
        self.spaces = {}
        for space in ALL_SPACES:
            self.spaces.setdefault(space, startingMarks.get(space, BLANK))

    def drawBoard(self):
        # Display a text-representation of the board.
        print(f'{self.spaces[TL]}|{self.spaces[TM]}|{self.spaces[TR]}')
        print('-----')
        print(f'{self.spaces[ML]}|{self.spaces[MM]}|{self.spaces[MR]}')
        print('-----')
        print(f'{self.spaces[BL]}|{self.spaces[BM]}|{self.spaces[BR]}')

    def isWinner(self, mark):
        bo, m = self.spaces, mark # These shorter names make the following code shorter.
        return ((bo[TL] == m and bo[TM] == m and bo[TR] == m) or # across the top
                (bo[ML] == m and bo[MM] == m and bo[MR] == m) or # across the middle
                (bo[BL] == m and bo[BM] == m and bo[BR] == m) or # across the bottom
                (bo[TL] == m and bo[ML] == m and bo[BL] == m) or # down the left side
                (bo[TM] == m and bo[MM] == m and bo[BM] == m) or # down the middle
                (bo[TR] == m and bo[MR] == m and bo[BR] == m) or # down the right side
                (bo[TL] == m and bo[MM] == m and bo[BR] == m) or # diagonal
                (bo[TR] == m and bo[MM] == m and bo[BL] == m)) # diagonal

    def getPlayerMove(self):
        # Let the player type in their move.
        move = None
        while move not in ALL_SPACES or not self.spaces[move] == BLANK:
            print('What is your move? (TL TM TR ML MM MR BL BM BR)')
            move = input().upper()
        return move

    def isFull(self):
        # Return True if every space on the board has been taken. Otherwise return False.
        for space in ALL_SPACES:
            if self.spaces[space] == BLANK:
                return False
        return True

    def setSpace(self, space, mark):
        # Sets the space on the board to mark, if it is valid.
        if mark not in (X, O, BLANK):
            raise ValueError('invalid mark for space')
        self.spaces[space] = mark

if __name__ == '__main__':
    main()