Simple Multiplication Table with Tkinter for Python 3.x

multiplication_table.py

#  multiplication_table.py
#  
#  Copyright 2015 Ericson Willians (Rederick Deathwill) <EricsonWRP@ERICSONWRP-PC>
#  
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#  
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#  
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
#  MA 02110-1301, USA.
#  
#  

import tkinter as tk

class App(tk.Frame):
    
    DEFAULT_PADY = 2
    
    def __init__(self, master=None):
        tk.Frame.__init__(self, master)
        self.config()
        self.grid()
        self.create_widgets()
        
    def config(self):
        self.master.title("x*y")
        
    def create_widgets(self):
        top = self.winfo_toplevel() 
        top.rowconfigure(0, weight=1)
        top.columnconfigure(0, weight=1)
        self.rowconfigure(0, weight=1)
        self.columnconfigure(0, weight=1)
        self.result_label = tk.Label(self, text="Input a number: ")
        self.result_label.grid(row=0, column=0, pady=App.DEFAULT_PADY, sticky=tk.W + tk.E + tk.N + tk.S)
        self.number_entry = tk.Entry(self, justify=tk.RIGHT)
        self.number_entry.grid(row=1, column=0, pady=App.DEFAULT_PADY, sticky=tk.W + tk.E + tk.N + tk.S)
        self.show_button = tk.Button(self, text="ok", width=4, command=self.update_result)
        self.show_button.grid(row=2, column=0, pady=App.DEFAULT_PADY, sticky=tk.SE)
        
    def update_result(self):
        self.result_label["text"] = '\n'.join([
            "{x}*{y} = {result}".format(x = int(self.number_entry.get()), 
                                            y = n, result = int(self.number_entry.get())*n) 
                                                for n in range(11)])

if __name__ == '__main__':
    App().mainloop()