Create random number between 1 and 7 based on a random function that return a number between 1 and 5

rand7.py

import unittest
import random

def rand5():
    return random.randint(1,5)

def rand7():
    result = 0
    while True:
        result = 5 * (rand5() - 1) + rand5()
        if result <= 21:
            break
    #result is now a random between 1 and 25
    return (result%7) + 1


class RandomTest(unittest.TestCase):

    def test_random7(self):
        for index in range(100000):
            random_number = rand7()
            self.assertLessEqual(random_number, 7)
            self.assertGreaterEqual(random_number, 1)

if __name__ == "__main__":
    unittest.main()