如何使用pygame将变量的值显示为文本

import pygame
import sys

pygame.init()
width, height = 800, 600
screen = pygame.display.set_mode((width, height))

def draw_text(text, font, color, x, y):
    text_surface = font.render(text, True, color)
    text_rect = text_surface.get_rect()
    text_rect.center = (x, y)
    screen.blit(text_surface, text_rect)

while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()

    # 更新变量的值
    variable = 42

    # 清空屏幕
    screen.fill((255, 255, 255))

    # 绘制文本
    font = pygame.font.Font(None, 36)
    draw_text("Variable: " + str(variable), font, (0, 0, 0), width // 2, height // 2)

    # 更新屏幕显示
    pygame.display.flip()