python编写多线程程序并测速

import threading import time ind=2 def single():     for j in range(ind):         for i in range(5000):             print(i*2) def s():     for i in range(5000):         print(i*2) def multi():     threa=[]     for j in range(ind):         threa.append(threading.Thread(target=s))     for t in threa:         t.start()     for t in threa:         t.join() if __name__ == '__main__':     start=time.time()     single()     end=time.time()     sum=0     sum1=0     sum=end-start     start=time.time()     multi()     end=time.time()     sum1=end-start     print('single',sum,'multi',sum1)