Python线程Event

import threading
import time
event=threading.Event()
class MythreadA(threading.Thread):
    def run(self):
        event.wait()
        print(self.name,":Good Morning")
        event.clear()
        time.sleep(2)
        event.set()
        event.wait()
        time.sleep(2)
        print(self.name,"I am fine tks")
        event.set()
class MythreadB(threading.Thread):
    def run(self):
        print(self.name,"Good Morning")
        event.set()
        time.sleep(1)
        event.wait()
        print(self.name,"How are you")
        event.clear()
        event.wait()
        event.set()
def main():
    John=MythreadA()
    John.name="John"
    Simth=MythreadB()
    Simth.name="Simth"
    John.start()
    Simth.start()
if __name__=="__main__":
    main()