import tkinter

key = 0

def key_down(e):
    global key
    key = e.keycode

def main_proc():
    label['text'] = key
    root.after(100, main_proc)

root = tkinter.Tk()
root.title('即時按鍵輸入處理')
root.bind('<KeyPress>', key_down)
label = tkinter.Label(font = ('Times New Roman', 80))
label.pack()
main_proc()
root.mainloop()