title: convert string into Quantlib Date()
body: <p>I am reading some parameters data from a csv and I am struggling to convert the date so that it is accepted by the class Date()</p>
  
  <p>I have tried that:</p>
  
  <pre><code>d = datetime.date(datetime.strptime('2011-03-07','%Y-%m-%d'))
  Date(d)
  </code></pre>
  
  <p>but it returns:</p>
  
  <blockquote>
    <p>NotImplementedError: Wrong number or type of arguments for overloaded
    function 'new_Date'.</p>
  </blockquote>