title: Assertion error on python while running rowcol test
body: <p>I am running a test rowcol basically multiplying the row and column to get the out come to see if it is equal to the original. I did this on paper how matrices are done. But when I run it it always says the the assertion error is not equal. 
  I've double checked everything to make sure no extra indention no extra numbers or anything.</p>
  
  <p>code:</p>
  
  <pre><code>def test_rowcol_product_1( self ):
          """ Row col product """
          row = [4,5,6]
          col = [3,7,11]
          self.assertEqual( rowcol_product(row, col), 4*3 + 5*7 + 6*11 )
  </code></pre>
  
  <p>error I receive: </p>
  
  <pre><code>self.assertEqual( rowcol_product(row, col), 4*3 + 5*7 + 6*11 )
  AssertionError: None != 113
  </code></pre>