.get() invoke after a button nested press

[deanhystad]

You still have mainloop() appearing twice in you code. It can only appear once.

You still have this loop that will create thousands of login windows a second once you remove the extra mainloop().

while login_verified == False and run_program == True:
    LoginWindow = tk.TopLevel()

You did not read enough about simple dialog. I my example I have two entry fields. Not sure how you missed that if you ran the code.