Minesweeper in tkinter; why does this happen?

Question

I am trying to make minesweeper using buttons in tkinter, and it's my first time using tkinter. My only problem is that i don't know how to create buttons that react differently to different keys (i want 'f' to create a flag and left click to "open" the tile), whilst still being able to pass on a variable that is different from when the button was created to a function... Description will get clearer after code...

    from tkinter import *
    from random import *
    master = Tk()
    bomb_positions = []

    for i in range (160):
        random = randint(0, 2)

        if random == 0 or 1:                              #These are 'safe' buttons
            btn = Button(master, width=2)
            btn.bind('<ButtonRelease-1>', lambda event, i=i: check(i))
                                      #Correct value of i when check(i) is called at event
            btn.bind('f', lambda event, i=i: place_flag(i))
                                      #Diffrent value if i when place_flag(i) is called at event
            btn.pack()
            btn.grid(row=row, column=col)

        if random == 2:                              #These are 'bombs'
            btn = Button(master, width=2)
            btn.bind('<ButtonRelease-1>', function3)
            btn.bind('f', lambda event, i=i: place_flag(i))    #Same problem as above
            btn.pack()
            bomb_positions.append(i)

When running the program the specific value i for each button gets in to function1. However, when i press 'f' over any button the 'place_flag()' function is called, but the value of i is different. (Interestingly, the value of i that is used when the 'place_flag()' function is called starts off by not giving any value. For each press of TAB on an inactive part of the tkinter window, the value goes from 1 and increases with 1 for each press of Tab.)

I want the value of i to be the same as the value that follows through to the 'check()' function, and I have no idea what causes my problem. Any ideas?

(Very new to programming so sorry for incorrect terminology and fuzzy explanations... Happy for all the help I can get!)

Answer 1

You weren't keeping track of your buttons so you would have no way to edit them in the future. I'd added a btnList to you your code to keep track of them. I've also created a new binding for <Enter> which will set the focus on the button which currently has the mouse over the top of it.

This code should allow you to hover over a button, press the 'f' key and it will change the text of the button from blank to "F".

I've now also updated your code so that when the user clicks on a square it checks to see if the square is in the bomb_positions list; if it is it print "Boom!!" to the console and places a * in the button, if it is not a bomb then it places an O.

Hopefully the changes I've made will help you to carry on with the game.

from tkinter import *
from random import *
master = Tk()
bomb_positions = []

def function3(event):
    print("Function3")


def place_flag(square):
    print("PlaceFlag")
    btnList[square]['text'] = 'F'

def check(square,btn):
    print("Check ",square, btn)
    if square in bomb_positions:
        print("Booommmmm!!!")
        btnList[square]['text'] = '*'
    else:
        btnList[square]['text'] = 'O'

def setFocus(event):
    event.widget.focus_set()

btnList = []

for i in range (160):

    random = randint(0, 2)
    row, col = divmod(i,16)

    if random == 0 or 1:                              #These are 'safe' buttons
        btn = Button(master, width=2)
        btn.bind('<ButtonRelease-1>', lambda event, i=i: check(i,btn))
                                  #Correct value of i when check(i) is called at event
        btn.bind('f', lambda event, i=i: place_flag(i))
                                  #Diffrent value if i when place_flag(i) is called at event
        #btn.pack()
        btn.grid(row=row, column=col)

    if random == 2:                              #These are 'bombs'
        btn = Button(master, width=2)
        btn.bind('<ButtonRelease-1>', lambda event, i=i: check(i,btn))
        btn.bind('f', lambda event, i=i: place_flag(i))    #Same problem as above
        btn.grid(row=row, column=col)
        bomb_positions.append(i)
    btn.bind("<Enter>",setFocus)
    btnList.append(btn)



master.mainloop()

With a simple change the buttons could be colour coded to show whether there is a bomb in them or not too.

def check(square,btn):
    print("Check ",square, btn)
    if square in bomb_positions:
        print("Booommmmm!!!")
        btnList[square]['bg'] = 'red'
        btnList[square]['text'] = '*'
    else:
        btnList[square]['bg'] = 'green'

Answer 2

If you are trying to implement Minesweeper in Python, you might find this to be a helpful starting point for your code:

import tkinter
import functools

class MineSweep(tkinter.Frame):

    @classmethod
    def main(cls, width, height):
        root = tkinter.Tk()
        window = cls(root, width, height)
        root.mainloop()

    def __init__(self, master, width, height):
        super().__init__(master)
        self.__width = width
        self.__height = height
        self.__build_buttons()
        self.grid()

    def __build_buttons(self):
        self.__buttons = []
        for y in range(self.__height):
            row = []
            for x in range(self.__width):
                button = tkinter.Button(self)
                button.grid(column=x, row=y)
                button['text'] = '?'
                command = functools.partial(self.__push, x, y)
                button['command'] = command
                row.append(button)
            self.__buttons.append(row)

    def __push(self, x, y):
        print('Column = {}\nRow = {}'.format(x, y))

if __name__ == '__main__':
    MineSweep.main(10, 10)

If you are looking for a more fully-featured program to modify instead, you might want to use this as a starting point instead:

import tkinter
import functools
import random
from tkinter.simpledialog import askstring, Dialog
from tkinter.messagebox import showinfo
import os.path

################################################################################

class MineSweep(tkinter.Frame):

    @classmethod
    def main(cls, width, height, mines, scores):
        root = tkinter.Tk()
        root.resizable(False, False)
        root.title('MineSweep')
        window = cls(root, width, height, mines, scores)
        root.protocol('WM_DELETE_WINDOW', window.close)
        root.mainloop()

################################################################################

    def __init__(self, master, width, height, mines, scores):
        super().__init__(master)
        self.__width = width
        self.__height = height
        self.__mines = mines
        self.__wondering = width * height
        self.__started = False
        self.__playing = True
        self.__scores = ScoreTable()
        self.__record_file = scores
        if os.path.isfile(scores):
            self.__scores.load(scores)
        self.__build_timer()
        self.__build_buttons()
        self.grid()

    def close(self):
        self.__scores.save(self.__record_file)
        self.quit()

    def __build_timer(self):
        self.__secs = tkinter.IntVar()
        self.__timer = tkinter.Label(textvariable=self.__secs)
        self.__timer.grid(columnspan=self.__width, sticky=tkinter.EW)
        self.__after_handle = None

    def __build_buttons(self):
        self.__reset_button = tkinter.Button(self)
        self.__reset_button['text'] = 'Reset'
        self.__reset_button['command'] = self.__reset
        self.__reset_button.grid(column=0, row=1,
                                 columnspan=self.__width, sticky=tkinter.EW)
        self.__reset_button.blink_handle = None
        self.__buttons = []
        for y in range(self.__height):
            row = []
            for x in range(self.__width):
                button = tkinter.Button(self, width=2, height=1,
                                        text='?', fg='red')
                button.grid(column=x, row=y+2)
                command = functools.partial(self.__push, x, y)
                button['command'] = command
                row.append(button)
            self.__buttons.append(row)

    def __reset(self):
        for row in self.__buttons:
            for button in row:
                button.config(text='?', fg='red')
        self.__started = False
        self.__playing = True
        self.__wondering = self.__width * self.__height
        if self.__after_handle is not None:
            self.after_cancel(self.__after_handle)
            self.__after_handle = None
        self.__secs.set(0)

    def __push(self, x, y, real=True):
        button = self.__buttons[y][x]
        if self.__playing:
            if not self.__started:
                self.__build_mines()
                while self.__buttons[y][x].mine:
                    self.__build_mines()
                self.__started = True
                self.__after_handle = self.after(1000, self.__tick)
            if not button.pushed:
                self.__push_button(button, x, y)
            elif real:
                self.__blink(button, button['bg'], 'red')
        elif real:
            self.__blink(button, button['bg'], 'red')

    def __blink(self, button, from_bg, to_bg, times=8):
        if button.blink_handle is not None and times == 8:
            return
        button['bg'] = (to_bg, from_bg)[times & 1]
        times -= 1
        if times:
            blinker = functools.partial(self.__blink, button,
                                        from_bg, to_bg, times)
            button.blink_handle = self.after(250, blinker)
        else:
            button.blink_handle = None

    def __tick(self):
        self.__after_handle = self.after(1000, self.__tick)
        self.__secs.set(self.__secs.get() + 1)

    def __push_button(self, button, x, y):
        button.pushed = True
        if button.mine:
            button['text'] = 'X'
            self.__playing = False
            self.after_cancel(self.__after_handle)
            self.__after_handle = None
            self.__blink(self.__reset_button, button['bg'], 'red')
        else:
            button['fg'] = 'SystemButtonText'
            count = self.__total(x, y)
            button['text'] = count and str(count) or ' '
            self.__wondering -= 1
            if self.__wondering == self.__mines:
                self.after_cancel(self.__after_handle)
                self.__after_handle = None
                self.__finish_game()

    def __finish_game(self):
        self.__playing = False
        score = self.__secs.get()
        for row in self.__buttons:
            for button in row:
                if button.mine:
                    button['text'] = 'X'
        if self.__scores.eligible(score):
            name = askstring('New Record', 'What is your name?')
            if name is None:
                name = 'Anonymous'
            self.__scores.add(name, score)
        else:
            showinfo('You did not get on the high score table.')
        HighScoreView(self, 'High Scores', self.__scores.listing())

    def __total(self, x, y):
        count = 0
        for x_offset in range(-1, 2):
            x_index = x + x_offset
            for y_offset in range(-1, 2):
                y_index = y + y_offset
                if 0 <= x_index < self.__width and 0 <= y_index < self.__height:
                    count += self.__buttons[y_index][x_index].mine
        if not count:
            self.__propagate(x, y)
        return count

    def __propagate(self, x, y):
        for x_offset in range(-1, 2):
            x_index = x + x_offset
            for y_offset in range(-1, 2):
                y_index = y + y_offset
                if 0 <= x_index < self.__width and 0 <= y_index < self.__height:
                    self.__push(x_index, y_index, False)

    def __build_mines(self):
        mines = [True] * self.__mines
        empty = [False] * (self.__width * self.__height - self.__mines)
        total = mines + empty
        random.shuffle(total)
        iterator = iter(total)
        for row in self.__buttons:
            for button in row:
                button.mine = next(iterator)
                button.pushed = False
                button.blink_handle = None

################################################################################

class ScoreTable:

    def __init__(self, size=10):
        self.__data = {999: [''] * size}

    def add(self, name, score):
        assert self.eligible(score)
        if score in self.__data:
            self.__data[score].insert(0, name)
        else:
            self.__data[score] = [name]
        if len(self.__data[max(self.__data)]) == 1:
            del self.__data[max(self.__data)]
        else:
            del self.__data[max(self.__data)][-1]

    def eligible(self, score):
        return score <= max(self.__data)

    def listing(self):
        for key in sorted(self.__data.keys()):
            for name in self.__data[key]:
                yield name, key

    def load(self, filename):
        self.__data = eval(open(filename, 'r').read())

    def save(self, filename):
        open(filename, 'w').write(repr(self.__data))

################################################################################

class HighScoreView(Dialog):

    def __init__(self, parent, title, generator):
        self.__scores = generator
        super().__init__(parent, title)

    def body(self, master):
        self.__labels = []
        for row, (name, score) in enumerate(self.__scores):
            label = tkinter.Label(master, text=name)
            self.__labels.append(label)
            label.grid(row=row, column=0)
            label = tkinter.Label(master, text=str(score))
            self.__labels.append(label)
            label.grid(row=row, column=1)
        self.__okay = tkinter.Button(master, command=self.ok, text='Okay')
        self.__okay.grid(ipadx=100, columnspan=2, column=0, row=row+1)
        return self.__okay

    def buttonbox(self):
        pass

################################################################################

if __name__ == '__main__':
    MineSweep.main(10, 10, 10, 'scores.txt')

Reference: ActiveState Code » Recipes » MineSweep