import numpy as np
my_arr = np.arange(1000000)
my_list = list(range(1000000))
%time for _ in range(10): my_arr2 = my_arr * 2
%time for _ in range(10): my_list2 = [x * 2 for x in my_list]
CPU times: user 9.16 ms, sys: 326 µs, total: 9.48 ms
Wall time: 9.51 ms
CPU times: user 511 ms, sys: 139 ms, total: 650 ms
Wall time: 659 ms