def test_underscore(self):
     self.assertFalse(is_word("not_a_word"))
 def test_exclamation_mark(self):
     self.assertFalse(is_word("what!"))
 def test_digits(self):
     self.assertFalse(is_word("hell0"))
 def test_comma(self):
     self.assertFalse(is_word("yes,"))
 def test_question_mark(self):
     self.assertFalse(is_word("what?"))
 def test_hyphen(self):
     self.assertTrue(is_word("self-report"))
 def test_period(self):
     self.assertFalse(is_word("No."))
 def test_apostrophe(self):
     self.assertTrue(is_word("don't"))
 def test_one_word(self):
     self.assertTrue(is_word("ice"))
     self.assertTrue(is_word("cream"))
 def test_with_space(self):
     self.assertFalse(is_word("ice cream"))
 def test_capitalized(self):
     self.assertTrue(is_word("Trey"))
 def test_empty_string(self):
     self.assertFalse(is_word(""))