title: Converting unicode string to hexadecimal representation
body: <p>I want to convert unicode string to its hexadecimal representation. 
  For example, <code>u'\u041a\u0418\u0421\u0410'</code> should be converted to <code>"\xD0\x9A\xD0\x98\xD0\xA1\xD0\x90"</code>. I tried the code below (python 2.7):</p>
  
  <pre><code>unicode_username.encode("utf-8").encode("hex")
  </code></pre>
  
  <p>However, I get a string:</p>
  
  <pre><code>'d09ad098d0a1d090'
  </code></pre>
  
  <p>Any suggestions how I can get <code>\xD0\x9A\xD0\x98\xD0\xA1\xD0\x90</code>?</p>