title: TypeError: unsupported operand type(s) python web2py
body: <p>The code below is giving me the following error: 
  <code>TypeError: unsupported operand type(s) for +: 'int' and 'Row'</code></p>
  
  <pre><code>import datetime
  #product withholding in days
  days = (0)
  
  pdays = db(db.product.withholding_period&gt;0).select().first()
  
  wdate = db(db.stock_task.completed_date&gt;0).select().first()
  
  fdate = wdate + datetime.timedelta(days+pdays)
  </code></pre>
  
  <p>Can anyone explain what causes this error and how it can be solved?</p>