Python Question tic tac toe Objects that TTT will use board
Python Question : tic tac toe
Objects that TTT will use
boardTurtle
xTurtle
oTurtle
winTurtle
board -> list of digits 0-8
0 1 2
3 4 5
6 7 8
Player names
Functions that TTT will use
playTTT()
# create \'tools\'
# get player names
# draw board
# alternate play between X and O until game ends
getPlayerNames()
# two name, first is X, second is O
# return tuple of names (strings)
getmove(board)
# return digit 0-8 that is unoccupied on board
drawboard(t, cellsize)
# draw centered on screen
drawX(t, cell)
# draw X in specified cell, half of cellsize
drawO(t, cell)
# draw O in specified cell, half of cellsize
drawConcentric(t, radius)
# helper function for drawO
drawMidline(t, length)
# helper function for drawX, drawboard
gameOver(board)
# check whether X has won, 0 has won,
# game is draw, or none of the these
# return \'X\', \'O\', \'D\' or \'-\' respectively
Solution
# Tic Tac Toe
import random
def drawBoard(board):
# This function prints out the board that it was passed.
# \"board\" is a list of 10 strings representing the board (ignore index 0)
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():
# Lets the player type which letter they want to be.
# Returns a list with the player’s letter as the first item, and the computer\'s letter as the second.
letter = \'\'
while not (letter == \'X\' or letter == \'O\'):
print(\'Do you want to be X or O?\')
letter = input().upper()
# the first element in the list is the player’s letter, the second is the computer\'s letter.
if letter == \'X\':
return [\'X\', \'O\']
else:
return [\'O\', \'X\']
def whoGoesFirst():
# Randomly choose the player who goes first.
if random.randint(0, 1) == 0:
return \'computer\'
else:
return \'player\'
def playAgain():
# This function returns True if the player wants to play again, otherwise it returns False.
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(bo, le):
# Given a board and a player’s letter, this function returns True if that player has won.
# We use bo instead of board and le instead of letter so we don’t have to type as much.
return ((bo[7] == le and bo[8] == le and bo[9] == le) or # across the top
(bo[4] == le and bo[5] == le and bo[6] == le) or # across the middle
(bo[1] == le and bo[2] == le and bo[3] == le) or # across the bottom
(bo[7] == le and bo[4] == le and bo[1] == le) or # down the left side
(bo[8] == le and bo[5] == le and bo[2] == le) or # down the middle
(bo[9] == le and bo[6] == le and bo[3] == le) or # down the right side
(bo[7] == le and bo[5] == le and bo[3] == le) or # diagonal
(bo[9] == le and bo[5] == le and bo[1] == le)) # diagonal
def getBoardCopy(board):
# Make a duplicate of the board list and return it the duplicate.
dupeBoard = []
for i in board:
dupeBoard.append(i)
return dupeBoard
def isSpaceFree(board, move):
# Return true if the passed move is free on the passed board.
return board[move] == \' \'
def getPlayerMove(board):
# Let the player type in their move.
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):
# Returns a valid move from the passed list on the passed board.
# Returns None if there is no valid move.
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):
# Given a board and the computer\'s letter, determine where to move and return that move.
if computerLetter == \'X\':
playerLetter = \'O\'
else:
playerLetter = \'X\'
# Here is our algorithm for our Tic Tac Toe AI:
# First, check if we can win in the next move
for i in range(1, 10):
copy = getBoardCopy(board)
if isSpaceFree(copy, i):
makeMove(copy, computerLetter, i)
if isWinner(copy, computerLetter):
return i
# Check if the player could win on their next move, and block them.
for i in range(1, 10):
copy = getBoardCopy(board)
if isSpaceFree(copy, i):
makeMove(copy, playerLetter, i)
if isWinner(copy, playerLetter):
return i
# Try to take one of the corners, if they are free.
move = chooseRandomMoveFromList(board, [1, 3, 7, 9])
if move != None:
return move
# Try to take the center, if it is free.
if isSpaceFree(board, 5):
return 5
# Move on one of the sides.
return chooseRandomMoveFromList(board, [2, 4, 6, 8])
def isBoardFull(board):
# Return True if every space on the board has been taken. Otherwise return False.
for i in range(1, 10):
if isSpaceFree(board, i):
return False
return True
print(\'Welcome to Tic Tac Toe!\')
while True:
# Reset the board
theBoard = [\' \'] * 10
playerLetter, computerLetter = inputPlayerLetter()
turn = whoGoesFirst()
print(\'The \' + turn + \' will go first.\')
gameIsPlaying = True
while gameIsPlaying:
if turn == \'player\':
# Player’s turn.
drawBoard(theBoard)
move = getPlayerMove(theBoard)
makeMove(theBoard, playerLetter, move)
if isWinner(theBoard, playerLetter):
drawBoard(theBoard)
print(\'Hooray! You have won the game!\')
gameIsPlaying = False
else:
if isBoardFull(theBoard):
drawBoard(theBoard)
print(\'The game is a tie!\')
break
else:
turn = \'computer\'
else:
# Computer’s turn.
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)
break
else:
turn = \'player\'
if not playAgain():
break




