тест производительности работы со списками

# проверка производительности кода создания списков разными способами
# src: https://pythonist.ru/predstavlenie-spiskov-v-yazyke-python/
from datetime import datetime as dt


def variant1(limit):
    l1 = [x ** 2 for x in range(1, limit) if x % 2 == 0]


def variant2(limit):
    sqr = []
    for x in range(1, limit):
        if x % 2 == 0:
            sqr.append(x ** 2)


def variant3(limit):
    l0 = list(map(lambda x: x ** 2, filter(lambda x: x % 2 == 0, range(1, limit))))


if __name__ == '__main__':
    limit = 10 ** 8
    timestart = dt.now()
    variant1(limit)
    timeend = dt.now()
    print(f"variant 1 {timeend - timestart}")

    timestart = dt.now()
    variant2(limit)
    timeend = dt.now()
    print(f"variant 2 {timeend - timestart}")

    timestart = dt.now()
    variant3(limit)
    timeend = dt.now()
    print(f"variant 3 {timeend - timestart}")

"""
 Intel(R) Core(TM) i7-8750H CPU @ 2.20GHz
 uname -a
 Linux arrow 5.6.0-kali2-amd64 #1 SMP Debian 5.6.14-1kali1 (2020-05-25) x86_64 GNU/Linux

 variant 1 0:00:12.477574
 variant 2 0:00:13.516124
 variant 3 0:00:18.117899
"""