def func1():
    l1 = range(10000)
    l2 = range(10000, 20000)
    i = 2
    for j in l2:
        l1.insert(i, j)
        i += 1
    return l1
	
def func2():
    l1 = range(10000)
    l2 = range(10000, 20000)
    l1.reverse()
    l2.reverse()
    for i in l2:
        l1.insert(-2, i)
    return l1
	
import timeit

print timeit.timeit(func1,number=10)
print timeit.timeit(func2,number=10)