这是我的代码，我面临的问题是 NameError: name 'hour' is not defined

Question

def wishMe ():
    hour = int(datetime.datetime.now().hour)
if hour>0 and hour<12:
 Speak ("Good Morning!")

elif hour>12 and hour<18:
 Speak ("Good Afternoon!")

if __name__=="__main__":
    wishMe()