Roman vs. Rostik

import random
from time import time

dbl = lambda x: x << 1  # x * 2
hlf = lambda x: x >> 1  # x / 2

gen = lambda count, max: [random.randrange(0, max) for x in range(1, count)]

roman = lambda a: map(dbl, list(a[:hlf(len(a))])) + map(hlf, list(a[hlf(len(a)):]))

rostik = lambda a: list(x << 1 for x in a[:len(a) >> 1]) + list(x >> 1 for x in a[len(a) >> 1:])

m = gen(1000000, 100)

start = time()
roman(m)
print("Roman: ", time() - start)

start = time()
rostik(m)
print("Rostik", time() - start)