title: How to solve error: Zip argument #1 must support iteration
body: <p>I have two test methods with the same problem, here are the original methods in the main class:</p>
  
  <pre><code>def get_num_words(self, word_part):
      """ 1 as default, may want 0 as an invalid case """
      if word_part[3] == '0a':
          self.num_words = 10
      else:
          self.num_words = int(word_part[3])
      return self.num_words
  
  def get_num_pointers(self, before_at):
      self.num_pointers = int(before_at.split()[-1])
      return self.num_pointers
  </code></pre>
  
  <p>And here are the two test classes:</p>
  
  <pre><code>def test_get_num_words(self):
      word_part = ['13797906', '23', 'n', '04', 'flood', '0', 'inundation', '0', 'deluge', '0', 'torrent', '0', '005', '@', '13796604', 'n', '0000', '+', '00603894', 'a', '0401', '+', '00753137', 'v', '0302', '+', '01527311', 'v', '0203', '+', '02361703', 'v', '0101', '|', 'an', 'overwhelming', 'number', 'or', 'amount;', '"a', 'flood', 'of', 'requests";', '"a', 'torrent', 'of', 'abuse"']
      expected = 04
      real = self.wn.get_num_words(word_part)
      for r, a in zip(real, expected):
          self.assertEqual(r, a)
  
  def test_get_num_pointers(self):
      before_at = '13797906 23 n 04 flood 0 inundation 0 deluge 0 torrent 0 005'
      expected = 5
      real = self.wn.get_num_pointers(before_at)
      for r, a in zip(real, expected):
          self.assertEqual(r, a)
  </code></pre>
  
  <p>This is the error they are giving out: <code>TypeError: zip argument #1 must support iteration</code>
  The program works fully and these are the only 2 tests not working in 20 different tests.</p>