title: Page not found error in Django REST framework tutorial
body: <p>I am doing the Django REST Framework Tutorial, and I got to the part when they add the view for an individual snippet (view snippet_detail, tutorial 2). When I start the server and point the browser to url <a href="http://127.0.0.1:8000/snippets" rel="nofollow noreferrer">http://127.0.0.1:8000/snippets</a>, it returns the 3 snippets I have created before (ids:1,2,3), fine. At url <a href="http://127.0.0.1:8000/snippets/2" rel="nofollow noreferrer">http://127.0.0.1:8000/snippets/2</a>, it returns only the snippet 2, perfect. But when I try <a href="http://127.0.0.1:8000/snippets/1" rel="nofollow noreferrer">http://127.0.0.1:8000/snippets/1</a>, it raises a Page not found error:</p>
  
  <pre><code>Request URL:    http://127.0.0.1:8000/snippets/1/
  
  Using the URLconf defined in tutorial.urls, Django tried these URL 
  patterns, in this order:
    ^ ^snippets/$
    ^ ^snippets/(?P&lt;pk&gt;[0-9]+)$
    ^admin/
  The current path, snippets/1/, didn't match any of these.
  </code></pre>
  
  <p>I don't understand why snippets/1 doesn't match the second url pattern. Can someone please clarify this error and help me overcome this.</p>