Question

In Python: Please complete the following two tasks in Tic Tac Toe:

1. Allow the user to choose heads/tails to see if the user goes first or the computer and alter your code accordingly.

2. Allow the user to play again.

Add a simple strategy for the AI to play against the user.

Answer 1

Here is the code with both your requirements fulfilled.

Have a nice day :)

import random

def drawBoard(board):
        print(board[1] + '|' + board[2] + '|' + board[3])
        print('-+-+-')
        print(board[4] + '|' + board[5] + '|' + board[6])
        print('-+-+-')
        print(board[7] + '|' + board[8] + '|' + board[9])


def inputPlayerLetter():
        letter=''
        while not(letter=='X' or letter=='O'):
                print("Do you want to be 'X' or 'O'?")
                letter = input().upper()

        if letter == 'X':
                return ['X','O']
        else:
                return ['O','X']


def whoGoesFirst():
        print('Do you want to go first? (Yes or No)')
        if  input().lower().startswith('y'):
                return 'player'
        else:
                return 'computer'


def playAgain():
        print('Do you want to play again? (Yes or No)')
        return input().lower().startswith('y')


def makeMove(board, letter, move):
        board[move] = letter


def isWinner(board,letter):
        return ((board[1]==letter and board[2]==letter and board[3]==letter) or
                        (board[4]==letter and board[5]==letter and board[6]==letter) or
                        (board[7]==letter and board[8]==letter and board[9]==letter) or
                        (board[1]==letter and board[4]==letter and board[7]==letter) or
                        (board[2]==letter and board[5]==letter and board[8]==letter) or
                        (board[3]==letter and board[6]==letter and board[9]==letter) or
                        (board[1]==letter and board[5]==letter and board[9]==letter) or
                        (board[3]==letter and board[5]==letter and board[7]==letter))


def getBoardCopy(board):
        dupBoard = []
        for i in board:
                dupBoard.append(i)
        return dupBoard


def isSpaceFree(board, move):
        return board[move] == ' '


def getPlayerMove(board):
        move = '' 
        while move not in '1 2 3 4 5 6 7 8 9'.split() or not isSpaceFree(board,int(move)):
                print('What is your next move? (1-9)')
                move = input()
        return int(move)


def chooseRandomMoveFromList(board, movesList):
        possibleMoves = []
        for i in movesList:
                if isSpaceFree(board, i):
                        possibleMoves.append(i)

        if len(possibleMoves) != 0:
                return random.choice(possibleMoves)
        else:
                return None


def minimax(board, depth, isMax, alpha, beta, computerLetter):
        if computerLetter == 'X':
                playerLetter = 'O'
        else:
                playerLetter = 'X'
        if isWinner(board, computerLetter):
                return 10
        if isWinner(board, playerLetter):
                return -10
        if isBoardFull(board):
                return 0
        if isMax:
                best = -1000
                for i in range(1,10):
                        if isSpaceFree(board, i):
                                board[i] = computerLetter
                                best = max(best, minimax(board, depth+1, not isMax, alpha, beta, computerLetter) - depth)
                                alpha = max(alpha, best)
                                board[i] = ' '
                                if alpha >= beta:
                                        break
                return best
        else:
                best = 1000
                for i in range(1,10):
                        if isSpaceFree(board, i):
                                board[i] = playerLetter
                                best = min(best, minimax(board, depth+1, not isMax, alpha, beta, computerLetter) + depth)
                                beta = min(beta, best)
                                board[i] = ' '
                                if alpha >= beta:
                                        break
                return best


def findBestMove(board, computerLetter):
        if computerLetter == 'X':
                playerLetter = 'O'
        else:
                playerLetter = 'X'
        bestVal = -1000
        bestMove = -1
        for i in range(1,10):
                if isSpaceFree(board, i):
                        board[i] = computerLetter
                        moveVal = minimax(board, 0, False, -1000, 1000, computerLetter)
                        board[i] = ' '
                        if moveVal > bestVal:
                                bestMove = i
                                bestVal = moveVal
        return bestMove


def isBoardFull(board):
        for i in range(1,10):
                if isSpaceFree(board, i):
                        return False
        return True


print('\nWelcome to Tic Tac Toe!\n')
print('Reference of numbering on the board')
drawBoard('0 1 2 3 4 5 6 7 8 9'.split())
print('')

while True:
        theBoard = [' '] * 10
        playerLetter, computerLetter = inputPlayerLetter()
        turn = whoGoesFirst()
        print('The ' + turn + ' will go first.')
        gameIsPlaying = True
        while gameIsPlaying:
                if turn == 'player':
                        drawBoard(theBoard)
                        move = getPlayerMove(theBoard)
                        makeMove(theBoard, playerLetter, move)
                        if isWinner(theBoard, playerLetter):
                                drawBoard(theBoard)
                                print('You won the game')
                                gameIsPlaying = False
                        else:
                                if isBoardFull(theBoard):
                                        drawBoard(theBoard)
                                        print('The game is a tie')
                                        break
                                else:
                                        turn = 'computer'
                else:
                        move = findBestMove(theBoard, computerLetter)
                        makeMove(theBoard, computerLetter, move)
                        if isWinner(theBoard, computerLetter):
                                drawBoard(theBoard)
                                print('You lose the game')
                                gameIsPlaying = False
                        else:
                                if isBoardFull(theBoard):
                                        drawBoard(theBoard)
                                        print('The game is a tie')
                                        break
                                else:
                                        turn = 'player'
        if not playAgain():
                break