Tkinter Toplevel

Tkinter Toplevel belongs to Tkinter desktop UI. Create Tk(), add this widget, pack or grid it, then mainloop() — without mainloop the window never appears.

Tkinter Toplevel — output: Tk() then Toplevel(text='Hello Asha') then pack → mainloop. Run real Tkinter on your laptop to open the window.

Trap for Tkinter Toplevel: writing command=fn() with brackets. That calls the function immediately. Pass the function name: command=fn.