import tkinter as tkfrom tkinter import * my_w = tk.Tk()my_w.geometry("200x200")  # Size of the window my_w.title("www.plus2net.com")  # Adding a title# create one lebel my_str = tk.StringVar()l1 = tk.Label(my_w,  textvariable=my_str )l1.grid(row=1,column=2) my_str.set("Hi I am main window")# add one button b1 = tk.Button(my_w, text='Clik me to open new window',               command=lambda:my_open())b1.grid(row=2,column=2) def my_open():    my_w_child=Toplevel(my_w) # Child window     my_w_child.geometry("200x200")  # Size of the window     my_w_child.title("www.plus2net.com")    my_str1 = tk.StringVar()    l1 = tk.Label(my_w_child,  textvariable=my_str1 )    l1.grid(row=1,column=2)     my_str1.set("Hi I am Child window")    def my_fun():        my_w.config(bg='red')        my_w_child.grab_set()    b3 = tk.Button(my_w_child, text='Disable parent',                   command=lambda:my_w_child.grab_set())    b3.grid(row=2,column=2)    b4 = tk.Button(my_w_child, text='Enable parent',                   command=lambda:my_w_child.grab_release())    b4.grid(row=3,column=2)my_w.mainloop()