title: scrapy item loader return list not single value
body: <p>I am using scrapy 0.20.</p>
  
  <p>I want to use item loader </p>
  
  <p>this is my code:</p>
  
  <pre><code>l = XPathItemLoader(item=MyItemClass(), response=response)
          l.add_value('url', response.url)
          l.add_xpath('title',"my xpath")
          l.add_xpath('developer', "my xpath")
  return l.load_item()
  </code></pre>
  
  <p>I got the result in the json file. the <code>url</code> is a list. The <code>title</code> is a list. The <code>developer</code> is a list.</p>
  
  <p>How to extract single value instead of the list?</p>
  
  <p><strong>Should I make an item pipeline for that? I hope there is a faster way</strong></p>