Question

from tkinter import *

class GameBoard(Frame):
  def __init__(self):
    Frame.__init__(self)
    self.master.title("test")
    self.grid()
    #button frame
    self.__buttonPane = Frame(self)
    self.__buttonPane.grid()
    #buttons
    self.__buttonA1 = Button(self.__buttonPane,text = "A1",command = self._close)
    self.__buttonA1.grid()

  def _close(self):
    GameBoard().destroy()


def main():
  GameBoard().mainloop()

main()

How would I make my function for close to work?

Answer 1

GameBoard()

creates a new instance of GameBoard. Therefore:

GameBoard().destroy()

creates a new instance and calls destroy() on it which has no effect on the existing instance.

You want access the current instance in your _close() method which is done through self:

def _close(self):
    self.destroy()

However, this only destroys the frame (and its child windows, like the button), not the top level window (master).

To completely close the UI, you could call self.master.destroy() or simply self.quit():

def _close(self):
    self.quit()