[Tutor] Lights game

[Ismael Garrido]

Hello list.

I'd really appreciate any comments, particulary regarding style 
corrections. I'm a newbie...

Thanks!
Ismael


import random
import tkMessageBox
from Tkinter import *

class GUI:
    def __init__(self):
        self._crearGUI()

    def _crearGUI(self):
        self.root = Tk()
        self.root.title("Lights")
        self.botones = [[0,0,0],[0,0,0],[0,0,0]]
        for i in range(3):
            for j in range(3):
                action = lambda n=i, m=j: self._accion(n,m)
                self.botones[i][j] = Button(self.root, height=5, 
width=10, command=action)
                self.botones[i][j].grid(row=i, column=j, padx= 4, pady=4)

        self._updateBotones()
        self.root.mainloop()

    def _accion(self, i, j):
        self._click(i, j)
        try:
            self._checkWin()
        except ValueError:
            tkMessageBox.showinfo(title = "You won!", message = "You 
rock, kid!")

            if True == tkMessageBox.askyesno(title="What shall we do?", 
message="Play another?"):
                self.root.destroy()
                lights.__init__() ## Is this... too ugly? Is there a 
beter way?
                self.__init__()
            else:
                self.root.destroy()
    def _updateBotones(self):
        for i in range(3):
            for j in range(3):
                if lights.tablero[i][j] == True:
                    self.botones[i][j].configure(bg="red")
                else:
                    self.botones[i][j].configure(bg="grey")

    def _click(self, i, j):
        lights.click(i,j)
        self._updateBotones()

    def _checkWin(self):
        conteo = 0
        for i in range(3):
            for j in range(3):
                if lights.tablero[i][j] == True: conteo +=1
        if conteo == 9:
            print "GANO"
            raise ValueError
           
        return

class Luces:
    def __init__(self):
        self.tablero = [[0,0,0],[0,0,0],[0,0,0]]
        self._hacerTablero()
 
    def _hacerTablero(self):
        for i in range(3):
            for j in range(3):
                self.tablero[i][j] = not random.randint(0,1)

    def _cambiarCelda(self, i, j):
        self.tablero[i][j] = not self.tablero[i][j]

    def _descartarNegativos(self, n):
        if n < 0:
            raise IndexError
        return n

    def click(self, i,j):
        self._cambiarCelda(i,j)
        try:
            self._cambiarCelda(self._descartarNegativos(i-1), j)
        except IndexError:
            pass
        try:
            self._cambiarCelda(self._descartarNegativos(i+1), j)
        except IndexError:
            pass
        try:
            self._cambiarCelda(i, self._descartarNegativos(j-1))
        except IndexError:
            pass
        try:
            self._cambiarCelda(i, self._descartarNegativos(j+1))
        except IndexError:
            pass

if __name__ == '__main__':
    lights = Luces()
    lightsGUI = GUI()