# -*- coding: utf-8 -*-
from Tkinter import *
def Nul1(event):
    print('Hello')
def Nul2(event):
    btn1.configure(state='disabled')
root = Tk()
root.title( 'Observer' )
root.geometry( '400x400' )
btn1 = Button(root,
             text="Кнопка 1",
             #width=15,height=5,
             bg="white",fg="black",font="Arial 12")
btn2 = Button(root,
             text="Кнопка 2",
             #width=15,height=5,
             bg="white",fg="black",font="Arial 12")
btn1.bind("<Button-1>", Nul1)
btn1.pack()
btn2.bind("<Button-1>", Nul2)
btn2.pack()
root.mainloop()

def Nul1(event):
    if event.widget["stare"] != "disabled":
        print('Hello')

 root.iconbitmap('<Путь к иконке>')