Yet another Tic-Tac-Toe (with AI, using tkinter)

GOTO10 · May-22-2020, 04:31 PM

Hi Everyone,

Here is my stab at a Tic-Tac-Toe game using tkinter. Player controls "X" and makes moves by using numeric input. My number one goal here was to have an AI that can't be defeated, so please let me know if you find a sequence that wins! The AI was done through brute force by starting out with a few obvious checks and then adding new ones as I found new ways to win a game, so it is somewhat haphazardly cobbled together. I did make one pass through the code to get rid of global variables and consolidate some code into functions, so it is now less of a jumbled mess than it previously was.

Any and all critiques or suggestions are welcome!

        
          
          
              
              import sys
from tkinter import *
from tkinter import font as tkfont
 
class Gameboard:
    def __init__(self):
        self.tk = Tk()
        self.tk.title("Tic-Tac-Toe")
        self.tk.resizable(0, 0)
        self.tk.wm_attributes("-topmost", 1)
        self.wld = [0] * 3
        self.gameover = False
        self.gameclose = False
        self.gamecanvas = None
        self.startgame()
        self.tk.mainloop()
    def startgame(self):
        if self.gameover == True and self.gamecanvas is not None:
            self.gamecanvas.destroy()
            self.gameover = False
        self.board = [0] * 9
        self.turncount = 1
        self.gamecanvas = Canvas(self.tk, width=400, height=400)
        self.gamecanvas.pack()
        self.gamecanvas.bind_all('<KeyPress-y>', self.restart)
        self.gamecanvas.bind_all('<KeyPress-Y>', self.restart)
        self.gamecanvas.bind_all('<KeyPress-n>', self.endgame)
        self.gamecanvas.bind_all('<KeyPress-N>', self.endgame)
        self.gamecanvas.bind_all('<KeyPress-0>', self.playZero)
        self.gamecanvas.bind_all('<KeyPress-1>', self.playOne)
        self.gamecanvas.bind_all('<KeyPress-2>', self.playTwo)
        self.gamecanvas.bind_all('<KeyPress-3>', self.playThree)
        self.gamecanvas.bind_all('<KeyPress-4>', self.playFour)
        self.gamecanvas.bind_all('<KeyPress-5>', self.playFive)
        self.gamecanvas.bind_all('<KeyPress-6>', self.playSix)
        self.gamecanvas.bind_all('<KeyPress-7>', self.playSeven)
        self.gamecanvas.bind_all('<KeyPress-8>', self.playEight)
        self.gamecanvas.bind_all('<KeyPress-8>', self.playEight)
        self.gamecanvas.bind_all('<KeyPress-Return>', self.closegame)
        labels = plotBoard(self.board)
        showBoard(self.gamecanvas,labels)
    def restart(self,evt):
        if self.gameover == True:
            self.startgame()
    def endgame(self,evt):
        if self.gameover == True:
            self.gamecanvas.delete('all')
            smallfont = tkfont.Font(family="Arial", size=15)
            self.gamecanvas.create_text(200, 50, font=smallfont, text = 'Thanks for playing!', fill = 'blue')
            winstext = ('Wins: ' + str(self.wld[0]))
            lossestext = ('Losses: ' + str(self.wld[1]))
            drawstext = ('Draws: ' + str(self.wld[2]))
            self.gamecanvas.create_text(200, 100, font=smallfont, text = winstext, fill = 'blue')
            self.gamecanvas.create_text(200, 150, font=smallfont, text = lossestext, fill = 'blue')
            self.gamecanvas.create_text(200, 200, font=smallfont, text = drawstext, fill = 'blue')
            self.gamecanvas.create_text(200, 300, font=smallfont, text = 'Hit Enter to leave.', fill = 'blue')
            self.gameclose = True
    def closegame(self,evt):
        if self.gameover == True and self.gameclose == True:
            self.tk.destroy()
            sys.exit()
    def advanceTurn(self):
        self.turncount += 1
        labels = plotBoard(self.board)
        showBoard(self.gamecanvas,labels)
        winner = checkWin(self.board,self.turncount,self.wld)
        if winner in ['O','X','D']:
            winMessage(self.gamecanvas,winner)
            self.gameover = True
        else:
            self.board = aiMove(self.board,self.turncount)
            self.turncount += 1
            labels = plotBoard(self.board)
            showBoard(self.gamecanvas,labels)
            winner = checkWin(self.board,self.turncount,self.wld)
            if winner in ['O','X','D']:
                winMessage(self.gamecanvas,winner)
                self.gameover = True
    def playZero(self,evt):
        if self.board[0] == 0 and self.gameover == False:
            self.board[0] = 1
            self.advanceTurn()
    def playOne(self,evt):
        if self.board[1] == 0 and self.gameover == False:
            self.board[1] = 1
            self.advanceTurn()
    def playTwo(self,evt):
        if self.board[2] == 0 and self.gameover == False:
            self.board[2] = 1
            self.advanceTurn()
    def playThree(self,evt):
        if self.board[3] == 0 and self.gameover == False:
            self.board[3] = 1
            self.advanceTurn()
    def playFour(self,evt):
        if self.board[4] == 0 and self.gameover == False:
            self.board[4] = 1
            self.advanceTurn()
    def playFive(self,evt):
        if self.board[5] == 0 and self.gameover == False:
            self.board[5] = 1
            self.advanceTurn()
    def playSix(self,evt):
        if self.board[6] == 0 and self.gameover == False:
            self.board[6] = 1
            self.advanceTurn()
    def playSeven(self,evt):
        if self.board[7] == 0 and self.gameover == False:
            self.board[7] = 1
            self.advanceTurn()
    def playEight(self,evt):
        if self.board[8] == 0 and self.gameover == False:
            self.board[8] = 1
            self.advanceTurn()
 
def plotBoard(board):
    ## check values of the board and assign number, X, or O to a list
    currentBoard=['']*9
    for i in range(0,9):
        if board[i] == 0:
            currentBoard[i] = str(i)
        elif board[i] == 1:
            currentBoard[i] = 'X'
        elif board[i] == 2:
            currentBoard[i] = 'O'
    return currentBoard
 
def showBoard(canvas,board):
    ## draw the board
    canvas.delete('all')
    canvas.create_line(150, 50, 150, 350)
    canvas.create_line(250, 50, 250, 350)
    canvas.create_line(50, 150, 350, 150)
    canvas.create_line(50, 250, 350, 250)
    canvas.create_text(100, 100, text=board[0], font=('Times', 80))
    canvas.create_text(200, 100, text=board[1], font=('Times', 80))
    canvas.create_text(300, 100, text=board[2], font=('Times', 80))
    canvas.create_text(100, 200, text=board[3], font=('Times', 80))
    canvas.create_text(200, 200, text=board[4], font=('Times', 80))
    canvas.create_text(300, 200, text=board[5], font=('Times', 80))
    canvas.create_text(100, 300, text=board[6], font=('Times', 80))
    canvas.create_text(200, 300, text=board[7], font=('Times', 80))
    canvas.create_text(300, 300, text=board[8], font=('Times', 80))
 
def checkWin(board,turncount,wld):
    ##check for X win
    if ((board[0] == board[1] == board[2] == 1) \
        or (board[0] == board[4] == board[8] == 1) \
        or (board[0] == board[3] == board[6] == 1) \
        or (board[3] == board[4] == board[5] == 1) \
        or (board[6] == board[4] == board[2] == 1) \
        or (board[6] == board[7] == board[8] == 1) \
        or (board[1] == board[4] == board[7] == 1) \
        or (board[2] == board[5] == board[8] == 1)):
        wld[0] += 1
        return 'X'
    ##check for O win
    elif ((board[0] == board[1] == board[2] == 2) \
        or (board[0] == board[4] == board[8] == 2) \
        or (board[0] == board[3] == board[6] == 2) \
        or (board[3] == board[4] == board[5] == 2) \
        or (board[6] == board[4] == board[2] == 2) \
        or (board[6] == board[7] == board[8] == 2) \
        or (board[1] == board[4] == board[7] == 2) \
        or (board[2] == board[5] == board[8] == 2)):
        wld[1] += 1
        return 'O'
    ##check for draw
    elif turncount == 10:
        wld[2] += 1
        return 'D'
    else:
        return None
 
def aiMove(board,turncount):
    ## on second turn, take middle square if open, or top left corner if X took middle
    if turncount == 2:
        if board[4] == 0:
            board[4] = 2
        else:
            board[0] = 2
    ## on any turn beyond second, check if O can win, then check if X can win
    ## and make the appropriate move to win or block
    elif (board[3] == board[6] == 2 and board[0] == 0)\
         or (board[1] == board[2] == 2 and board[0] == 0)\
         or (board[4] == board[8] == 2 and board[0] == 0):
        board[0] = 2
    elif (board[0] == board[2] == 2 and board[1] == 0)\
         or (board[4] == board[7] == 2 and board[1] == 0):
        board[1] = 2
    elif (board[0] == board[1] == 2 and board[2] == 0)\
         or (board[6] == board[4] == 2 and board[2] == 0)\
         or (board[5] == board[8] == 2 and board[2] == 0):
        board[2] = 2
    elif (board[0] == board[6] == 2 and board[3] == 0)\
         or (board[4] == board[5] == 2 and board[3] == 0):
        board[3] = 2
    elif (board[0] == board[8] == 2 and board[4] == 0)\
         or (board[3] == board[5] == 2 and board[4] == 0)\
         or (board[6] == board[2] == 2 and board[4] == 0)\
         or (board[1] == board[7] == 2 and board[4] == 0):
        board[4] = 2
    elif (board[3] == board[4] == 2 and board[5] == 0)\
         or (board[2] == board[8] == 2 and board[5] == 0):
        board[5] = 2
    elif (board[0] == board[3] == 2 and board[6] == 0)\
         or (board[4] == board[2] == 2 and board[6] == 0)\
         or (board[7] == board[8] == 2 and board[6] == 0):
        board[6] = 2
    elif (board[1] == board[4] == 2 and board[7] == 0)\
         or (board[6] == board[8] == 2 and board[7] == 0):
        board[7] = 2            
    elif (board[0] == board[4] == 2 and board[8] == 0)\
         or (board[6] == board[7] == 2 and board[8] == 0)\
         or (board[2] == board[5] == 2 and board[8] == 0):
        board[8] = 2
    elif (board[3] == board[6] == 1 and board[0] == 0)\
         or (board[1] == board[2] == 1 and board[0] == 0)\
         or (board[4] == board[8] == 1 and board[0] == 0):
        board[0] = 2
    elif (board[0] == board[2] == 1 and board[1] == 0)\
         or (board[4] == board[7] == 1 and board[1] == 0):
        board[1] = 2
    elif (board[0] == board[1] == 1 and board[2] == 0)\
         or (board[6] == board[4] == 1 and board[2] == 0)\
         or (board[5] == board[8] == 1 and board[2] == 0):
        board[2] = 2
    elif (board[0] == board[6] == 1 and board[3] == 0)\
         or (board[4] == board[5] == 1 and board[3] == 0):
        board[3] = 2
    elif (board[0] == board[8] == 1 and board[4] == 0)\
         or (board[3] == board[5] == 1 and board[4] == 0)\
         or (board[6] == board[2] == 1 and board[4] == 0)\
         or (board[1] == board[7] == 1 and board[4] == 0):
        board[4] = 2
    elif (board[3] == board[4] == 1 and board[5] == 0)\
         or (board[2] == board[8] == 1 and board[5] == 0):
        board[5] = 2
    elif (board[0] == board[3] == 1 and board[6] == 0)\
         or (board[4] == board[2] == 1 and board[6] == 0)\
         or (board[7] == board[8] == 1 and board[6] == 0):
        board[6] = 2
    elif (board[1] == board[4] == 1 and board[7] == 0)\
         or (board[6] == board[8] == 1 and board[7] == 0):
        board[7] = 2            
    elif (board[0] == board[4] == 1 and board[8] == 0)\
         or (board[6] == board[7] == 1 and board[8] == 0)\
         or (board[2] == board[5] == 1 and board[8] == 0):
        board[8] = 2      
##    If we get to this point, it is at least the 4th turn and there
##    is no win possible for either player, so we start checking for
##    more specific scenarios
    ## If it's the 4th turn and X went in the center first,
    ## then O is in top left and any move by X other than
    ## bottom right should have already been countered
    ## thanks to win condition checks
    elif (board[4] == board[8] == 1 and turncount == 4 and board[6] == 0):
        board[6] = 2
    ## check if 7 and 5 are occupied and 8 is open (any other scenario
    ## of two side squares occupied by X is already countered)
    elif (board[7] == board[5] == 1 and board[8] == 0):
        board[8] = 2
    ## check for circumstance where X played a corner followed by non-adjacent
    ## side square, and take the opposite corner
    elif (board[2] == 1 and (board[7] == 1 or board[3] == 1) and board[6] == 0):
        board[6] = 2
    elif (board[0] == 1 and (board[7] == 1 or board[5] == 1) and board[8] == 0):
        board[8] = 2
    ## check for circumstance where X occupies opposite corners and
    ## play a side to prevent any win opportunities
    elif (board[0] == 1 and board[8] == 1 and board[7] == 0):
        board[7] = 2
    elif (board[2] == 1 and board[6] == 1 and board[5] == 0):
        board[5] = 2
    ## if we get to this point, just take the first open square we can find
    else:
        move = 0
        for i in range(0,9):
            if board[i] == 0:
                move = i
                break
        board[move] = 2
    return board
 
def winMessage(canvas,winner):
    fatfont = tkfont.Font(family="Arial", size=75, weight="bold")
    slimfont = tkfont.Font(family="Arial", size=45)
    smallfont = tkfont.Font(family="Arial", size=15)
    if winner == 'X':
        canvas.create_text(200, 100, font=fatfont, text = 'YOU', fill = 'red')
        canvas.create_text(200, 175, font=fatfont, text = 'WON!', fill = 'red')
        canvas.create_text(200, 270, font=slimfont, text = 'IMPOSSIBLE!', fill = 'red')
        canvas.create_text(200, 360, font=smallfont, text = 'Enter Y to play again or N to quit.', fill = 'black')
    elif winner == 'O':
        canvas.create_text(200, 35, font=slimfont, text = 'O WINS!', fill = 'blue')
        canvas.create_text(200, 160, font=slimfont, text = 'GAME', fill = 'blue')
        canvas.create_text(200, 240, font=slimfont, text = 'OVER', fill = 'blue')
        canvas.create_text(200, 360, font=smallfont, text = 'Enter Y to play again or N to quit.', fill = 'black')
    elif winner == 'D':
        canvas.create_text(200, 35, font=slimfont, text = 'DRAW', fill = 'blue')
        canvas.create_text(200, 160, font=slimfont, text = 'GAME', fill = 'blue')
        canvas.create_text(200, 240, font=slimfont, text = 'OVER', fill = 'blue')
        canvas.create_text(200, 360, font=smallfont, text = 'Enter Y to play again or N to quit.', fill = 'black')
 
Gameboard()

            

        
      

pyzyx3qwerty · May-23-2020, 07:20 AM

Really good code.... though i am finding it difficult to win :)

**Larz60+** · May-24-2020, 02:10 AM

empty lines are your friend

GOTO10 · May-24-2020, 01:36 PM

(May-23-2020, 07:20 AM)pyzyx3qwerty Wrote: Really good code.... though i am finding it difficult to win :)

Thank you! My wife deserves most of the credit for the AI, as she beat it several times when I thought I was already done coding. Wink

(May-24-2020, 02:10 AM)Larz60+ Wrote: empty lines are your friend

Point taken, and I agree. I've changed up my style a bit in the code I'm working on now, including the addition of more white space for readability.

**Yoriz** · (This post was last modified: May-24-2020, 08:06 PM by Yoriz.)

Begin removing some duplicated parts

In the following methods

        
          
          
              
              def playZero(self, evt):
     if self.board[0] == 0 and self.gameover == False:
         self.board[0] = 1
         self.advanceTurn()
 
 def playOne(self, evt):
     if self.board[1] == 0 and self.gameover == False:
         self.board[1] = 1
         self.advanceTurn()
 
 def playTwo(self, evt):
     if self.board[2] == 0 and self.gameover == False:
         self.board[2] = 1
         self.advanceTurn()
 
 def playThree(self, evt):
     if self.board[3] == 0 and self.gameover == False:
         self.board[3] = 1
         self.advanceTurn()
 
 def playFour(self, evt):
     if self.board[4] == 0 and self.gameover == False:
         self.board[4] = 1
         self.advanceTurn()
 
 def playFive(self, evt):
     if self.board[5] == 0 and self.gameover == False:
         self.board[5] = 1
         self.advanceTurn()
 
 def playSix(self, evt):
     if self.board[6] == 0 and self.gameover == False:
         self.board[6] = 1
         self.advanceTurn()
 
 def playSeven(self, evt):
     if self.board[7] == 0 and self.gameover == False:
         self.board[7] = 1
         self.advanceTurn()
 
 def playEight(self, evt):
     if self.board[8] == 0 and self.gameover == False:
         self.board[8] = 1
         self.advanceTurn()

            

        
      

the only thing that changes is the board index number.
From the evt parameter, you can obtain the character of the key pressed using its char attribute.
A single function can be created to replace all of the number keys events

        
              def play_number(self, evt):
    index = int(evt.char)
    if self.board[index] == 0 and self.gameover == False:
        self.board[index] = 1
        self.advanceTurn()

The event binding now becomes

        
              self.gamecanvas.bind_all('<KeyPress-0>', self.play_number)
self.gamecanvas.bind_all('<KeyPress-1>', self.play_number)
self.gamecanvas.bind_all('<KeyPress-2>', self.play_number)
self.gamecanvas.bind_all('<KeyPress-3>', self.play_number)
self.gamecanvas.bind_all('<KeyPress-4>', self.play_number)
self.gamecanvas.bind_all('<KeyPress-5>', self.play_number)
self.gamecanvas.bind_all('<KeyPress-6>', self.play_number)
self.gamecanvas.bind_all('<KeyPress-7>', self.play_number)
self.gamecanvas.bind_all('<KeyPress-8>', self.play_number)

This also has repeated code that only the number changes and can be replaced with

        
              for number in range(9):
    self.gamecanvas.bind_all(f'<KeyPress-{number}>', self.play_number)

The remaining key binds

        
              self.gamecanvas.bind_all('<KeyPress-y>', self.restart)
self.gamecanvas.bind_all('<KeyPress-Y>', self.restart)
self.gamecanvas.bind_all('<KeyPress-n>', self.endgame)
self.gamecanvas.bind_all('<KeyPress-N>', self.endgame)
self.gamecanvas.bind_all('<KeyPress-Return>', self.closegame)

only the key character and the bind method changes, this could be done by using a tuple

        
              key_binds = (('y', self.restart), ('Y', self.restart),
            ('n', self.endgame), ('N', self.endgame),
            ('Return', self.closegame))
for key, bind in key_binds:
    self.gamecanvas.bind_all(f'<KeyPress-{key}>', bind)

There is a repeated pattern here

        
              canvas.create_text(100, 100, text=board[0], font=('Times', 80))
canvas.create_text(200, 100, text=board[1], font=('Times', 80))
canvas.create_text(300, 100, text=board[2], font=('Times', 80))
canvas.create_text(100, 200, text=board[3], font=('Times', 80))
canvas.create_text(200, 200, text=board[4], font=('Times', 80))
canvas.create_text(300, 200, text=board[5], font=('Times', 80))
canvas.create_text(100, 300, text=board[6], font=('Times', 80))
canvas.create_text(200, 300, text=board[7], font=('Times', 80))
canvas.create_text(300, 300, text=board[8], font=('Times', 80))

that could be looped

        
              index = 0
for y in (range(100, 400, 100)):
    for x in (range(100, 400, 100)):
        canvas.create_text(x, y, text=board[index], font=('Times', 80))
        index += 1

ndc85430 · May-25-2020, 02:16 PM

(May-22-2020, 04:31 PM)GOTO10 Wrote: My number one goal here was to have an AI that can't be defeated, so please let me know if you find a sequence that wins! The AI was done through brute force by starting out with a few obvious checks and then adding new ones as I found new ways to win a game, so it is somewhat haphazardly cobbled together.

The more "proper" way to do this is to implement the minimax algorithm, which models the game as a search tree. Finding the best move is done by assuming that the opponent plays optimally (i.e. chooses the best move each time) and finding the best result you can get given that. It's actually a relatively straightforward algorithm to implement. When performance becomes an issue (which certainly occurs in games like chess, because the search tree is so large), alpha-beta pruning is what you look at - it produces the same result as minimax, but is more efficient because it avoids searching parts of the tree that won't make any difference to the outcome.

Calli · May-25-2020, 03:31 PM

Please publish your full code when you are done this is a really cool project best of luck pal to you and your wife

Knight18 · May-25-2020, 04:54 PM

Impressive! I've got a question, I've only taken a brief look, but is this a learning bot? As in, will it learn from it's losses? Or is it just a bot designed to evaluate outcomes as they present themselves and pick the best option to win?

GOTO10 · (This post was last modified: May-25-2020, 08:36 PM by GOTO10.)

Thanks very much to everyone for the feedback, I sincerely appreciate it!

Yoriz, I love your suggestions. I was not aware of evt.char, so thanks particularly for bringing that to my attention.

ndc85430, I know nothing about game theory and had never heard of a minimax algorithm before your post, but I agree that it seems like a great approach to a game as simple as Tic-Tac-Toe. I don't expect to change the code that much at this point, but this is definitely something I'll research further for possible future projects.

Calli, I doubt I'll do much more with this beyond perhaps implementing Yoriz' suggestions for deduplication, but I appreciate your encouragement. Smile

Knight18, my code just evaluates options and does not learn from any errors (although Tic-Tac-Toe does seem like a great, simple way to experiment with machine learning). I start by choosing one of two options for the first move depending on what X did, and then all subsequent turns first check for win possibilities and then move on to making moves based on specific scenarios. More than once, I thought I had accounted for every scenario possible, only to have my alpha-tester wife find a way to beat it. When that happened, I just added additional evaluations to account for those scenarios.

Knight18 · May-26-2020, 06:48 AM

That's interesting. I suppose it's possible while playing Tic Tac Toe. On a game like chess or even checkers, accounting for every possible scenario would be almost impossible though. Machine learning would be a better idea for such games.

Yet another Tic-Tac-Toe (with AI, using tkinter)

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