gistfile1.py

import timeit
import threading

lst = [] 
def lf():
    del lst[:]
    for i in range(10000):
        lst.append(i)


def f1():
    lf()
    lf()

def f2():
    t = threading.Thread(target=lf)
    t.start()
    #t.join()
    t = threading.Thread(target=lf)
    t.start()
    t.join()
 
def main():
    t1 = timeit.Timer('f1()', 'from __main__ import f1')
    t2 = timeit.Timer('f2()', 'from __main__ import f2')
 
    for t in t1, t2:
        print(t.repeat(3, 100))
 
if __name__ == '__main__':
    main()