title: How to specify parameters on a Request using scrapy
body: <p>How do I pass parameters to a a request on a url like this:</p>
  
  <pre><code>site.com/search/?action=search&amp;description=My Search here&amp;e_author=
  </code></pre>
  
  <p>How do I put the arguments on the structure of a Spider Request, something like this exemple:</p>
  
  <pre><code>req = Request(url="site.com/",parameters={x=1,y=2,z=3})
  </code></pre>