b.py

from tkinter import filedialog,Tk
from PIL import Image

rt=Tk()
rt.withdraw()
ph=filedialog.askopenfilenames(title='选择图片文件',filetypes=[('png','.png')],initialdir='./')
il=[]
for i in ph:
    im=Image.open(i)
    il.append(im)
il[0].save('Rbot.gif',save_all=True,append_images=il[1:])