Python Tkinter keyboard using bind -

i have problem using bind option can click button in keyboard, , call function once key pressed. tried taking other codes have similar purpose , saw i'm doing pretty same, though still have problem must've missed. thankful if me this. here's code:

# -*- coding: utf-8 -*-  #imports tkinter import *         pil import imagetk, image import time import tkmessagebox  #===========================================================================================================================================# #tkinter class class app(frame):     def __init__(self, master=none):         frame.__init__(self, master)         self.pack()  #===========================================================================================================================================# #game pieces classes class board:     def __init__(self, rows = 7, columns = 6, picture_height = none, picture_width = none):         self.rows = rows         self.columns = columns         self.picture = imagetk.photoimage(image.open(r"c:\users\ariel\desktop\python\4inarow.gif"))         self.picture_height = self.picture.height()         self.picture_width = self.picture.width()      def create_and_pack(self, canvas):         board_item = canvas.create_image(700, 370, image = self.picture)      def __str__(self):         print "rows:", self.rows, "columns:", self.columns  class disk:     def __init__(self, player_number = none):         self.picture = imagetk.photoimage(image.open(r"c:\users\ariel\desktop\python\me" + str(player_number) + ".gif"))         self.player_number = player_number      def create_and_pack(self, canvas, x, y):         disk_item = canvas.create_image(x, y, image = self.picture)      def get_x_parameter(self, number):         #x growing 70~73 per number         x = 330         in range(7):             if number == i:                 x = x + * 72         return x      def get_y_parameter(self, number):         #y lowered 70~73 per number         y = 635         in range(6):             if number == i:                 y = y - * 72         return y      def place(self, canvas, x, y):         #first left down circle parameters         #480, 635         canvas.move(self.picture, x, y)      def __str__(self):         print "the disk's picture string:", self.picture, "the player disk's number:", self.player_number  #===========================================================================================================================================# #game class  class game:     def __init__(self, board = none, disk1 = none, disk2 = none):         self.disk1 = disk1         self.disk2 = disk2         self.board = board  #===========================================================================================================================================# #keyboardclass class keyboard:     def __init__(self, key_number = none):         self.key_number = key_number      def press_and_place(self, canvas, number, function):     canvas.focus_set()     canvas.bind("<" + str(number) + ">", function)  #===========================================================================================================================================# #main. myapp = app() myapp.master.title("4 in row") myapp.master.maxsize(2000, 1200) #---------------------------------------------------------------------------------------------------# gameboard = board(7, 6) firstplayerdisk = disk(1) secondplayerdisk = disk(2) gameclass = game(gameboard, firstplayerdisk, secondplayerdisk) #---------------------------------------------------------------------------------------------------# #creating canvas , placing disks , board. board_canvas = canvas(width = gameboard.picture_width, height = gameboard.picture_height) board_canvas.pack(expand=1, fill=both)  gameboard.create_and_pack(board_canvas) firstplayerdisk.create_and_pack(board_canvas, 330, 635) secondplayerdisk.create_and_pack(board_canvas, 260, 635) #---------------------------------------------------------------------------------------------------# #creating keyboard instance , placing first disk in last row in column of choice number_choice = 3 keyboardclass = keyboard(number_choice)  first_player_x = firstplayerdisk.get_x_parameter(number_choice) first_player_y = firstplayerdisk.get_y_parameter(number_choice) keyboardclass.press_and_place(board_canvas, number_choice, firstplayerdisk.place(board_canvas, first_player_x, first_player_y)) #---------------------------------------------------------------------------------------------------#  myapp.mainloop() 

thanks lot in advance.

i believe problem lies in line:

keyboardclass.press_and_place(board_canvas, number_choice, firstplayerdisk.place(board_canvas, first_player_x, first_player_y)) 

the third argument firstplayerdisk.place(board_canvas, first_player_x, first_player_y) none type

def place(self, canvas, x, y):     #first left down circle parameters     #480, 635     canvas.move(self.picture, x, y) 

returns none

from how bind keypress button in tkinter , this site, need pass function, is, firstplayerdisk.place (no parenthesis following it).