python3 线程

from time import ctime, sleep  
from threading import Thread  
 
def loop0():  
    print('start loop 0 at :',ctime())  
    sleep(4)  
    print('loop 0 at :',ctime())  
      
def loop1():  
    print('start loop 1 at:',ctime())  
    sleep(2)  
    print('loop 1 done at:',ctime())  
      
def main():  
    print('starting at:',ctime())  
    t1=Thread(target=loop0,name='loop0')  
    t2=Thread(target=loop1,name='loop1')  
      
    t1.start()  
    t2.start()  
    print('all done at:',ctime())  
  
if __name__=='__main__':  
    main()