Tkinter - window focus loss event
The event you are looking for is <FocusOut>.
import tkinter as tkdef on_focus_out(event): if event.widget == root: label.configure(text="I DON'T have focus")def on_focus_in(event): if event.widget == root: label.configure(text="I have focus")root = tk.Tk()label = tk.Label(width=30)label.pack(side="top", fill="both", expand=True)root.bind("<FocusIn>", on_focus_in)root.bind("<FocusOut>", on_focus_out)root.mainloop()