Automate the Boring Stuff with Python, Chaper 7 Practice Project, Strong Password Detection

strong-password-test.py

import unittest
from strong_password_detection import isStrongPassword

# A strong password is defined as one that is
# at least eight characters long,
# contains both uppercase and lowercase characters,
# and has at least one digit.


class TestStrongPasswords(unittest.TestCase):

    def test_empty_password(self):
        self.assertFalse(isStrongPassword(''))

    def test_less_than_eight_characters(self):
        self.assertFalse(isStrongPassword('rYer1'))

    def test_more_than_eight_characters(self):
        self.assertTrue(isStrongPassword('rnerrYer1rYer1rYer1'))

    def test_only_lower_case(self):
        self.assertFalse(isStrongPassword('rnerryer1ryer1ryer1'))

    def test_strong_password(self):
        self.assertTrue(isStrongPassword('T5hjmrtj'))


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

strong_password_detection.py

import re

# A strong password is defined as one that is
# at least eight characters long,
# contains both uppercase and lowercase characters,
# and has at least one digit.


def isStrongPassword(pw):
    return bool(re.match("""^(?=.*[a-z])    #contains lowercase characters
        (?=.*[A-Z])         # contains uppercase 
        (?=.*[0-9])         # has at least one digit
        (?=.{8,})"""        # at least eight characters long
                         , pw, re.VERBOSE))