How to on/off sub-window

on_off_sub-window.py

import ctypes
import tkinter


def show_or_hide_sub_window():
    if var.get():
        sub_window.deiconify()  #show
    else:
        sub_window.withdraw()   #hide


if __name__ == "__main__":
    ctypes.windll.shcore.SetProcessDpiAwareness(1)
    root = tkinter.Tk()
    root.title("main")

    #variable for checkbutton
    var = tkinter.BooleanVar(root)  
    
    #check button 
    cb = tkinter.Checkbutton(
        root,
        text = "sub_window",
        variable = var,
        command = show_or_hide_sub_window
    )
    cb.pack()

    #sub-window
    sub_window = tkinter.Toplevel(root)
    sub_window.title("sub")
    sub_window.withdraw()   #hide sub-window

    #label in sub-window
    l_s = tkinter.Label(
        sub_window,
        text = "Label in sub-window",
        bg = "lightblue",
    )
    l_s.pack()

    root.mainloop()