python - 为什么循环已经在 pyttsx3 中开始

Question

这是我的程序

engine = pyttsx3.init()
voices = engine.getProperty('voices')
engine.setProperty('voice', voices[1].id)
engine.setProperty('rate', 150)

def voice_alert(engine):
    engine.say('please wear mask')
    engine.runAndWait()

当 while 循环开始运行时调用 voice_alert 函数

while True:
    if mask < withoutMask:
            t = threading.Thread(target=voice_alert, args=(engine,))
            t.start()

错误：

raise RuntimeError('run loop not started')
RuntimeError: run loop not started