title: Xpath to get information in next sibling tag using Scrapy
body: <p>I'm trying to get my hands on Scrapy and right now I try to extract information from an etymology website: <a href="http://www.etymonline.com" rel="nofollow noreferrer">http://www.etymonline.com</a>
  Right now, I just want to get the words and their raw description. This is how a usual HTML code chunk is presented in etymonline:</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;dt&gt;
    &lt;a href="/index.php?term=address&amp;allowed_in_frame=0"&gt;address (n.)&lt;/a&gt;
    &lt;a href="http://dictionary.reference.com/search?q=address" class="dictionary" title="Look up address at Dictionary.com"&gt;
      &lt;img src="graphics/dictionary.gif" width="16" height="16" alt="Look up address at Dictionary.com" title="Look up address at Dictionary.com"/&gt;
    &lt;/a&gt;
  &lt;/dt&gt;
  &lt;dd&gt;
    1530s, "dutiful or courteous approach," from &lt;a href="/index.php?term=address&amp;allowed_in_frame=0" class="crossreference"&gt;address&lt;/a&gt; (v.) and from French &lt;span class="foreign"&gt;adresse&lt;/span&gt;. Sense of "formal speech" is from 1751. Sense of "superscription of a letter" is from 1712 and led to the meaning "place of residence" (1888).
  &lt;/dd&gt;
  </code></pre>
  
  <p>The word is contained in the <code>&lt;dt&gt;</code>tag and the description in the next sibling, <code>&lt;dd&gt;</code> tag.
  To get the list of word on a page like <a href="http://www.etymonline.com/index.php?l=a&amp;p=9&amp;allowed_in_frame=0" rel="nofollow noreferrer">http://www.etymonline.com/index.php?l=a&amp;p=9&amp;allowed_in_frame=0</a>, it's possible to write <code>word = sel.xpath('//dl/dt/a/text()').extract()</code>.</p>
  
  <p>Then I tried to loop over this list of words and extract the relevant information using this line of code <code>info = selInfo.xpath("//dl/dt[a='"+word[i]+"']/following-sibling::dd")</code>. But it doesn't seem to work. Any ideas ?</p>