moving circle every 2 secs (using class)

import pygame

import time

import sys

black = [0,0,0]

white = [255, 255, 255]

class Ball () :

    x = 0

    y = 0

    spd = 10

    size = 2

    color = white

    def move(self) :

        self.x += self.spd

        self.y += self.spd

    def draw(self, screen) :

        pygame.draw.circle(screen, self.color, [self.x, self.y], self.size)

sizeX = 400

sizeY = 500

size = [sizeX, sizeY]

pygame.init()

screen = pygame.display.set_mode(size)

pygame.display.set_caption('hell ball,?')

ball1 = Ball()

ball1.size = 3

ball1.x = 50

ball1.y = 50

ball1.color = black

for i in range(0, 200) :

    screen.fill(white)

    ball1.draw(screen)

    pygame.display.update()

    ball1.move()

    time.sleep(1)

while True :

    for event in pygame.event.get():

        if event.type == pygame.QUIT :

            pygame.quit()

            sys.exit()