title: How to match url pattern in tornado such as www.abc.com/?code=abcd1234
body: <p>I've googled a lot but cannot find.</p>
  
  <p>For example, my app is www.abc.com, how can I match this kind of url:</p>
  
  <pre><code>www.abc.com/?code=abcd1234
  </code></pre>
  
  <p>My handlers:</p>
  
  <pre><code>handers = [
    (r"/?", HomeHandler),
    (r"/?code=([^/]+)", OtherHandler),
  ]
  </code></pre>
  
  <p>the second pattern is wrong I think, and it always use the first</p>