Python Thread Synchronization in Multithreading

Program 1

import time
from  threading import *
l=Lock()
def printable(n):
    l.acquire()
    for i in range(1,11):
        print(n*i)
        time.sleep(1)
    l.release()  

# Calling (Main Thread)
T1=Thread(target=printable,args=(5,),name="First")
T2=Thread(target=printable,args=(7,),name="Second")
T3=Thread(target=printable,args=(9,),name="Third")
start=time.time()
T1.start()
T2.start()
T3.start()
T1.join()
T2.join()
T3.join()
end=time.time()
print("Total time",(end-start))