main.py

import timeit
import dis

def test1():
	a = [1,2,3,4,5]
	a = [9,8,7,6,5]
	
def test2():
	a = [1,2,3,4,5]
	a[:] = [9,8,7,6,5]

print("# test1()")
print(timeit.timeit('test1()','from __main__ import test1'))
dis.dis(test1)

print("# test2()")
print (timeit.timeit('test2()','from __main__ import test2'))
dis.dis(test2)