Tic Tac Toe

tictactoe.py

"""As I mentioned, a lot of this was initially derived from Making Games with Python by Al Sweigart"""

import random

def drawBoard(board):

	print '   |  ' + ' | '
	print ' ' + board[7]  + ' | ' + board[8] + ' | ' + board[9]
	print '   |  ' + ' | '
	print '-----------'
	print '   |  ' + ' | '
	print ' ' + board[4]  + ' | ' + board[5] + ' | ' + board[6]
	print '   |  ' + ' | '
	print '-----------'
	print '   |  ' + ' | '
	print ' ' + board[1]  + ' | ' + board[2] + ' | ' + board[3]
	print '   |  ' + ' | '


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


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


def whoGoesFirst():

	if random.randint(0, 1) == 0:
		return 'computer'
	else: 
		return 'player'


def playAgain():
	print "Do you want to play again? (yes or no)"
	return raw_input().lower().startswith('y')

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

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


def getBoardCopy(board):
	dupeBoard = []

	for i in board:
		dupeBoard.append(i)

	return dupeBoard

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 = raw_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 getComputerMove(board, computerLetter):
	if computerLetter == 'X':
		playerLetter = '0'
	else:
		playerLetter = 'X'


	for i in range(1, 10):
		copy = getBoardCopy(board)
		if isSpaceFree(copy, i):
			makeMove(copy, computerLetter, i)
			if isWinner(copy, playerLetter):
				return i


	move = chooseRandomMoveFromList(board, [1, 3, 7, 9])
	if move!= None:
		return move

	if isSpaceFree(board, 5):
		return 5


	return chooseRandomMoveFromList(board, [2, 4, 6, 8])

def isBoardFull(board):

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


print "Welcome to Tic Tac Toe"

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 "Hooray!  You've won the game!"
				gameIsPlaying = False
			else:
				if isBoardFull(theBoard):
					drawBoard(theBoard)
					print "The game is a tie!"
					break
				else:
					turn = 'computer'

		else:
			move = getComputerMove(theBoard, computerLetter)
			makeMove(theBoard, computerLetter, move)

			if isWinner(theBoard, computerLetter):
				drawBoard(theBoard)
				print "The computer has beaten you!  You lose!"
				gameIsPlaying = False
			else:
				if isBoardFull(theBoard):
					drawBoard(theBoard)
					print "The game is a tie!"
					break
				else:
					turn = 'player'

	if not playAgain():
		break