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I'm a code banger from way back trying to learn good Python style. Here is my attempt at the classic game. I'm trying to learn Tk, because I have a couple codes that need GUIs. Any suggestions or comments?

from tkinter import *
import random

# use a class definition to hold all my functions
class MyApp(Tk):
    def __init__(self):
        """ initialize the frame and widgets"""
        #load Tk

        #make a frame
        fr = Frame(self)

        #intialize operation buttons and the label
        self.player_button = Button(self, text="Me",
                                    command=lambda: self.do_start(TRUE),
                                    font=("Helvetica", 16))
        self.computer_button = Button(self, text="Computer",
                                      command=lambda: self.do_start(FALSE),
                                      font=("Helvetica", 16))
        self.exit_button = Button(self, text="Exit", command=self.do_exit,
                                  font=("Helvetica", 16))
        self.again_button = Button(self, text="again?", command=self.do_again,
                                   font=("Helvetica", 16))
        self.myLabel = Label(self, text="Who starts?", font=("Helvetica", 16))

        #initialize a list to use for my field buttons (note: 0 is not used)
        self.bList = [0,1,2,3,4,5,6,7,8,9]

        #use a loop to build my field buttons
        for i in range(1,10):
            self.bList[i] = Button(self, text="---",  #bList now button references
                                   command=lambda j=i: self.do_button(j),
                                   state=DISABLED, relief=RAISED, height=3,
                                   width=7, font=("Helvetica", 24))

        #grid everything into the frame
        self.myLabel.grid(row=0, columnspan=4)
        self.player_button.grid(row=1, column=0)
        self.computer_button.grid(row=1, column=2)
        self.exit_button.grid(row=5, column=0)
        self.again_button.grid(row=5, column=2)

        #use a loop to grid the field buttons
        myL = [[1,4,0], [2,4,1], [3,4,2],  #button number, row, column
               [4,3,0], [5,3,1], [6,3,2],
               [7,2,0], [8,2,1], [9,2,2]]
        for i in myL:
            self.bList[i[0]].grid(row=i[1], column=i[2])

    def do_start(self,player):
        """start the game, if player is TRUE, player make first move"""
        #turn Me, computer, and again? buttons off

        #reset the bState and mySums lists and the flags
        self.bState = [10,0,0,0,0,0,0,0,0,0]  #state of button 1-player -1-comp 0-open
        self.mySums = [0,0,0,0,0,0,0,0]       #sums of rows, columns and diagonals
        self.gameDone = FALSE
        self.specialDefense = FALSE

        #turn the field buttons on
        for i in range(1,10):

         #if player is true the player starts otherwise the computer starts
        self.myLabel.config(text="You are X, make a move")
        if player:
            self.turn = FALSE
            self.turn = TRUE

    def do_button(self, i):
        """handle a field button click"""
        #i is the number of the button that was pushed note: 1 through 9
        # if turn is true the computer made a move otherwie player
        if self.turn:
            myText = "-0-"
            self.turn = FALSE
            self.bState[i] = -1
            myText = "-X-"
            self.turn = TRUE
            self.bState[i] = 1

        #Disable the ith button and test if we are done
        self.bList[i].config(text=myText, state=DISABLED)

        # if it is the computer's turn and the game is not over make a move
        if (self.turn) and (not self.gameDone):

    def test_done(self):
        """test if the game is over"""
        #if there is not a 0 in bstate the game is done
        if not (0 in self.bState):
            self.myLabel.config(text="Draw, game over!")
            self.gameDone = TRUE

        #after doing sums look for 3 or -3 to find if there was a winner
        if 3 in self.mySums: #note 3 in mySums means player has won
            self.myLabel.config(text="You won!")
            self.gameDone = TRUE
        elif -3 in self.mySums: #note -3 in mySums means computer has won
            self.myLabel.config(text="Computer won!")
            self.gameDone = TRUE

    def do_sums(self):
        """put a list of the various row, column, and diagonal sums in mySums"""
        triples = [[1,2,3], [4,5,6], [7,8,9], #rows
                   [1,4,7], [2,5,8], [3,6,9], #columns
                   [1,5,9], [3,5,7]]          #diagonals
        count = 0
        for i in triples:
            self.mySums[count] = 0
            for j in i:
                self.mySums[count] += self.bState[j]

            count += 1

    def do_move(self):
        """computer picks a move to make"""
        #mix it up a little by starting with the center for first move sometimes
        if (not 1 in self.bState) and (not -1 in self.bState): #i.e. first move
            if random.random() < 0.20:   #20% of the time start in center

        #handle the case where player as made first move to a corner
        if (1 in self.bState) and (not -1 in self.bState):
            if self.bState.index(1) in [1,3,7,9]:
                self.specialDefense = TRUE

        #test if computer can win, if so do the move
        for i in range(1,10):
            if self.bState[i] == 0:
                self.bState[i] = -1   #make a trial move
                if -3 in self.mySums: #note -3 means computer has won
                    self.do_button(i) #make move if a win
                    self.bState[i] = 0 #switch back of not a win

        #test if player can win, if so block
        for i in range(1,10):
            if self.bState[i] == 0:
                self.bState[i] = 1   #make a trial move
                if 3 in self.mySums: #note 3 in bState means player has won
                    self.do_button(i) #block if player could win
                    self.specialDefense = FALSE #special defense no longer needed
                    self.bState[i] = 0 #switch back of not a win

        #for the second special defense move, pick a side (if not already done)
        if self.specialDefense:
            self.specialDefense = FALSE
            sides = [2,4,6,8]
            random.shuffle(sides)  #shuffle them so people don't get as bored
            for i in sides:
                if self.bState[i] == 0:

        #pick a corner if open
        corners = [1,3,7,9]
        random.shuffle(corners)   #shuffle them so people don't get as bored
        for i in corners:
            if self.bState[i] == 0:

        #take center if open
        if self.bState[5] == 0:

        #pick a side if open
        sides = [2,4,6,8]
        random.shuffle(sides)  #shuffle them so people don't get as bored
        for i in sides:
            if self.bState[i] == 0:

    def do_again(self):
        """reset everything to play again"""
        #reset my buttons and change the label
        self.myLabel.config(text="Who starts?")

        #disable the field buttons
        for i in range(1,10):
            self.bList[i].config(text="---", state=DISABLED)

    def do_exit(self):
        """destroy the frame when exit is pushed"""
# end of MyApp class

if __name__ == '__main__':
    root = MyApp()
    root.title("Carl's Tic Tac Toe")

In response to the answers:

I see the point about starting from 0. Is there a better way to do this? Part of the reason I did the buttons in a loop is that they all have the same formats. With this code I have the potential of having my first button different than the others.

num_buttons = 9
self.bList = [Button(#arguments)]
for i in range(1, num_buttons)

Since writing this I have now learned that making the first definition empty works i.e.,

num_buttons = 9
self.bList = []
for i in range(num_buttons)
share|improve this question
up vote 6 down vote accepted

Lambda Usage

I'm not a great fan of the lambda usage to create what are effectively partially applied functions in the self.player_button and self.computer_button. Instead I'd rather do something like:

import functools
self.player_button = Button(self, text="Me",
                                command=functools.partial(self.do_start, TRUE),
                                font=("Helvetica", 16))

This makes the intent more clear in my eyes.

List Buttons

You create a list of integers in self.bList = [0,1,2,3,4,5,6,7,8,9] and then immediately assign buttons to it. 10 is also a bit of a magic number here, so I'd replace it with something like:

num_buttons = 9
self.bList = [0]
for i in range(num_buttons):

Better still would just be dealing with 0 offsets, instead of having a 0 at the start and then indexing from 1. Keep everything as uniform as possible. It makes other parts of the program simpler as well:

for i in range(1,10):

can simply be:

for button in self.bList:


self.mySums = [0,0,0,0,0,0,0,0] is more clearly written as self.mySums = [0]*8


Try and stick to one variable naming style; there's self.player_button and self.myLabel for example. Doesn't really matter which one you pick, but consistency is key. Method names are probably a bit anaemic, things like do_button and do_again really need more descriptive names - do what with a button? Do what again?

Finally, TRUE should be True and likewise FALSE should be False.

share|improve this answer

Avoid using:

from _____ import *

I believe it violates the zen of python:

Explicit is better than implicit.

share|improve this answer
Could you also explain why its a bad idea? – James Khoury Dec 19 '12 at 23:10
Two advantages that I have found about keeping things explicit (1) keeping the namespace clean i.e., not having a lot of unused definitions, and (2) being clear on where you are getting particular definitions. For example, there could be several definitions of classes with the same name in different modules. If so what happens? – Carl Houtman Dec 21 '12 at 21:07
tkinter is one of the very few modules that are allowed to do this import style. – Renae Lider Sep 15 '14 at 18:44

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