Tkinter .bind() method

Question

Im trying to make a tic-tac-toe game, but every time i run the program, the function is automatically executing for some reason. code so far below:

from tkinter import *

root = Tk()
root.geometry('200x200')

x_turn = True

def button_clicked(b):
    global x_turn
    print('Executed')
        if x_turn is True:
            b.config(text='X')
            x_turn = False
        else:
            b.config(text='O')
            x_turn = True

button1 = Button(root, text='', width=6, height=2)
button1.bind('<Button1>', button_clicked(button1))
button1.grid(row=0, column=0)

button2 = Button(root, text='', width=6, height=2)
button2.bind('<Button1>', button_clicked(button2))
button2.grid(row=0, column=1)

button3 = Button(root, text='', width=6, height=2)
button3.bind('<Button1>', button_clicked(button3))
button3.grid(row=0, column=2)

button4 = Button(root, text='', width=6, height=2)
button4.bind('<Button1>', button_clicked(button4))
button4.grid(row=1, column=0)

button5 = Button(root, text='', width=6, height=2)
button5.bind('<Button1>', button_clicked(button5))
button5.grid(row=1, column=1)

button6 = Button(root, text='', width=6, height=2)
button6.bind('<Button1>', button_clicked(button6))
button6.grid(row=1, column=2)

button7 = Button(root, text='', width=6, height=2)
button7.bind('<Button1>', button_clicked(button7))
button7.grid(row=2, column=0)

button8 = Button(root, text='', width=6, height=2)
button8.bind('<Button1>', button_clicked(button8))
button8.grid(row=2, column=1)

button9 = Button(root, text='', width=6, height=2)
button9.bind('<Button1>', button_clicked(button9))
button9.grid(row=2, column=2)

root.mainloop()

When i run the program it automatically calls the function 9 times and i cant figure out why. is there some wierd rule i dont know about?

score 1 · Answer 1 · answered Apr 14 '16 at 03:12

1

It automatically calls button_clicked 9 times, because you told it to call it 9 times with your 9 buttonX.bind... calls.

The bind method takes a function as a parameter. You're not passing in a function, you're passing in the return value from button_clicked(b).

[button_clicked is a function, but button_clicked(some_parameter) means calling that function, and using the return value as the parameter]

There are a few ways to pass in a function that takes parameters to the bind method. One way is to pass in an anonymous lambda expression that will call your real function when it is called.

So, instead of this:

button1.bind('<Button1>', button_clicked(button1))

change all your calls to look something like this:

button1.bind('<Button1>', lambda: button_clicked(button1))

answered Apr 14 '16 at 03:12

Gerrat

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I get an error when i use lambda. – jjguidry Apr 14 '16 at 20:40
@jjguidry: maybe try: `button1.bind('', command=lambda: button_clicked(button1))`. – Gerrat Apr 14 '16 at 21:24
Nope :( "bind() got an unexpected keyword argument 'command'" – jjguidry Apr 14 '16 at 21:43
Hmm, I just went by the dup question to yours. The docs I liinked seem to suggest the parameter is called `func`. Try `button1.bind('', func=lambda: button_clicked(button1))`. If this doesn't work, you may have to ask a new question. – Gerrat Apr 14 '16 at 22:57
yeah that didnt work either :( thanks for your help though – jjguidry Apr 14 '16 at 23:01

Tkinter .bind() method

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