判断以下Python Tkinter代码运行后，点击按钮Greet时label框是否显示"Hello, World!"

import tkinter as tk
def greet():
    label.config(text="Hello, World!")
root = tk.Tk()
label = tk.Label(root, text="")
button = tk.Button(root, text="Greet", command=greet)
label.pack()
button.pack()
root.mainloop()