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The procedure is as follows:

import tkinter as tk
window = tk.Tk()
window.title("我的程序")
window.geometry('400x300')
var = tk.StringVar()
lable = tk.Label(window,textvariable = var,font = (('微軟雅黑'),12))
lable.pack()
on_hit = True
def run():
    global on_hit
    if on_hit == True:
        on_hit = False
        var.set('you hit me')
    else:
        on_hit = True
        var.set('')
button = tk.Button(window,text = 'hit',font = (('微軟雅黑'),12),command = run)
button.pack()
window.mainloop()

The effect of this program is that there is a button. When you press it, you hit me will appear. Press it again and it will disappear. This cycle
Why is the button written as button = tk.Button(window, text = 'Generate questions and answers' , font = (('Microsoft Yahei'),12), command = run()), add parentheses when calling the function, press the button again, it will always be you hit me, and the content in the label above will no longer change. ?