Basic unit test of function in Python

test_hand_val.py

import unittest

BUST_VAL = 22
ACE_HIGH = 11
ACE_LOW = 1

def calculate_hand_val(low_hand_val, num_aces):
    hand_val = low_hand_val

    for x in range(1, num_aces + 1):
        if (hand_val + (ACE_HIGH - ACE_LOW)) < BUST_VAL:
            print 'adding high'
            hand_val += (ACE_HIGH - ACE_LOW)
    return hand_val


class TestHandFunctions(unittest.TestCase):

    def test_hand_val(self):
        self.assertEqual(calculate_hand_val(1, 2), 21)
        self.assertEqual(calculate_hand_val(10, 1), 20)
        self.assertEqual(calculate_hand_val(10, 2), 21)


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