Tkinter中的通过/失败图像

from tkinter import *
from PIL import Image, ImageTk

root = Tk()

pass_image = Image.open("pass.png")
fail_image = Image.open("fail.png")

pass_image = pass_image.resize((200, 200))
fail_image = fail_image.resize((200, 200))

pass_photo = ImageTk.PhotoImage(pass_image)
fail_photo = ImageTk.PhotoImage(fail_image)

pass_label = Label(root, image=pass_photo)
pass_label.pack()

fail_label = Label(root, image=fail_photo)
fail_label.pack()

root.mainloop()