乒乓球比赛在tkinter中，检查球是否击中垂直球拍

import tkinter as tk

root = tk.Tk()
canvas = tk.Canvas(root, width=800, height=600)
canvas.pack()

racket = canvas.create_rectangle(380, 500, 420, 550, fill="blue")
ball = canvas.create_oval(395, 295, 405, 305, fill="red")

dx, dy = 2, 2
last_y = 0

def move_ball():
    canvas.move(ball, dx, dy)
    check_collision()
    root.after(10, move_ball)

def move_racket(event):
    global last_y
    canvas.move(racket, 0, event.y - last_y)
    last_y = event.y

def check_collision():
    ball_coords = canvas.coords(ball)
    racket_coords = canvas.coords(racket)

    if (ball_coords[2] >= racket_coords[0] and
        ball_coords[0] <= racket_coords[2] and
        ball_coords[3] >= racket_coords[1] and
        ball_coords[3] <= racket_coords[3]):
        dx = -dx

root.bind("<Motion>", move_racket)
move_ball()

root.mainloop()