У вашего броузера проблема в совместимости с HTML5
Python GUI(graphical user interface ) : This tutorial is very basic (introduction) , if you are already using tkinter , you can skip it .
I just showed you "minimum code require for every tkinter gui application" , this is only 4 lines of code
import tkinter
window = tkinter.Tk()
window.title("TITLE")
window.mainloop()