title: How to save one output file per request/URL?
body: <p>I'm using Scrapy and have set up:</p>
  
  <ul>
  <li>Items</li>
  <li>ItemLoader</li>
  <li>ItemPipeline</li>
  <li>start_requests using CSV to define multiple URLs</li>
  <li>Custom Writer</li>
  </ul>
  
  <p>I run the scraper simply:</p>
  
  <p><code>scrapy crawl scraper</code></p>
  
  <p>However, all output goes into one file.</p>
  
  <p>I would like one output file per request/URL?</p>
  
  <p>What am I missing?</p>