在pygame中更新一个数字

import pygame
from pygame.locals import *

pygame.init()
clock = pygame.time.Clock()

# 设置窗口尺寸
window_width, window_height = 800, 600
screen = pygame.display.set_mode((window_width, window_height))
pygame.display.set_caption("更新数字示例")

# 设置字体
font_size = 50
font = pygame.font.Font(None, font_size)

# 设置初始数字
num = 0

running = True
while running:
    screen.fill((255, 255, 255))  # 清空屏幕

    for event in pygame.event.get():
        if event.type == QUIT:
            running = False
        elif event.type == KEYDOWN:
            if event.key == K_UP:
                num += 1
            elif event.key == K_DOWN:
                num -= 1
        elif event.type == MOUSEBUTTONDOWN:
            # 根据鼠标按钮来更新数字
            if event.button == 1:  # 左键点击
                num += 1
            elif event.button == 3:  # 右键点击
                num -= 1

    # 绘制数字
    text_surface = font.render(str(num), True, (0, 0, 0))
    text_rect = text_surface.get_rect()
    text_rect.center = (window_width // 2, window_height // 2)
    screen.blit(text_surface, text_rect)

    pygame.display.flip()  # 更新屏幕显示
    clock.tick(60)  # 控制帧率

pygame.quit()