Moving ball pygame

from tkinter.constants import Y
from PyGame.ponggame4p import Yvelo
import pygame # importing the module
WIDTH = 800
HEIGHT = 600

pygame.init() # initializing the module
screen = pygame.display.set_mode((WIDTH, HEIGHT))  # making the window of size WIDTH and HEIGHT
pygame.display.set_caption('Pong Game') # setting the title of the window
clock = pygame.time.Clock()
run = True
speed = 2
y = 200
dy = speed
while run:           #-> while the game is running >>> 1 frame every time the loop runs
    screen.fill((0,0,0)) # r g b color inside
    clock.tick(60) # controlling the frame rate

    for event in pygame.event.get():  # for each event occuring in the window
        if event.type == pygame.QUIT:  # checking if the close button was pressed
            run = False     # update game status to stop (not running)

    y += dy # delta y -> change in y

    ball = pygame.draw.circle(screen, (255, 0, 0 ), (100, y), 25)

    if ball.bottom >= HEIGHT:
        dy = -speed
    elif ball.top <= 0:
        dy = speed

    pygame.display.flip()  # update our window with all the changes that we have done

pygame.quit() # close the window