RNG benchmark

rng.py

import os
from random import randint
from collections import Counter


def gen1(s):
    while True:
        s = s**7 % ~-2**67
        yield s % 6 + 1


def gen2(s):
    while True:
        s = 256
        while s >= 252:
            s = os.urandom(1)[0]
        yield s % 6 + 1


def gen3(s):
    while True:
        yield randint(1, 6)


def test(gen, n, i):
    g = gen(id(i))
    c = Counter(next(g) for _ in range(6*n))
    return sum((x-n)**2 for x in c.values()) ** 0.5


def run(t=5, n=10**5):
    for name, gen in (('short', gen1), ('urandom', gen2), ('randint', gen3)):
        print(name, sum(test(gen, n, i)/t for i in range(t)))


if __name__ == '__main__':
    run()