import tkinter

x = 0

def scroll_bg():
    global x
    x = x + 1
    if x == 480:
        x = 0
    canvas.delete('BG')
    canvas.create_image(x - 240, 150, image = img_bg, tag = 'BG')
    canvas.create_image(x + 240, 150, image = img_bg, tag = 'BG')
    root.after(50, scroll_bg)

root = tkinter.Tk()
root.title('捲動畫面')
canvas = tkinter.Canvas(width = 480, height = 300)
canvas.pack()
img_bg = tkinter.PhotoImage(file = 'images/park.png')
scroll_bg()
root.mainloop()