title: How do I get the attribute value as string with ScraPY xPath
body: <p>The Scrapy documentation says that to get a string representation of an element I have to do "string()"</p>
  
  <p>so I did:</p>
  
  <pre><code>for url in response.xpath('string(//a[@class="thumbnail"]/@href)'):
          print(url)
  </code></pre>
  
  <p>Without the string it prints all  but with string() there it just prints the Selector for the first element then closes the spider. What am I doing wrong?</p>