如何在pygame中循环播放音频文件的一部分？

import pygame
from pygame.locals import *

pygame.init()

window = pygame.display.set_mode((800, 600))
clock = pygame.time.Clock()

audio = pygame.mixer.Sound('audio_file.wav')

start_time = 0.0  # 循环播放的起始时间（秒）
duration = 5.0  # 循环播放的长度（秒）

loop_event = pygame.USEREVENT + 1
pygame.time.set_timer(loop_event, int(duration * 1000))  # 将事件定时触发

def play_audio():
    audio.play(maxtime=int(duration * 1000), fade_ms=100)  # 播放音频文件

running = True
while running:
    for event in pygame.event.get():
        if event.type == QUIT:
            running = False
        elif event.type == loop_event:
            play_audio()  # 循环播放音频文件

    window.fill((255, 255, 255))  # 填充窗口背景色
    pygame.display.update()
    clock.tick(60)  # 控制帧率

pygame.quit()