unittest_palindrome.py

#!/usr/bin/python3

import palindrome
import unittest

class TestPalindrome(unittest.TestCase):

    def test_valid(self):
        # check valid input strings
        self.assertTrue(palindrome.is_palindrome('kek'))
        self.assertTrue(palindrome.is_palindrome("Dammit, I'm mad!"))
        self.assertFalse(palindrome.is_palindrome('zzz'))
        self.assertFalse(palindrome.is_palindrome('cool'))

    def test_error(self):
        # check only the exception raised
        with self.assertRaises(ValueError):
            palindrome.is_palindrome('abc123')

        with self.assertRaises(TypeError):
            palindrome.is_palindrome(7)

        # check error message as well
        with self.assertRaises(ValueError) as cm:
            palindrome.is_palindrome('on 2 no')
        em = str(cm.exception)
        self.assertEqual(em, 'Characters other than alphabets and punctuations')

        with self.assertRaises(ValueError) as cm:
            palindrome.is_palindrome('to')
        em = str(cm.exception)
        self.assertEqual(em, 'Less than 3 alphabets')

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