title: Encode string as hex bytes
body: <p>I have a string '123456ffffffff'. How do I get the following </p>
  
  <pre><code>[0x12, 0x34, 0x56, 0xff, 0xff, 0xff, 0xff]
  </code></pre>
  
  <p>The input string will only contain digits. The output could be a bytearray or simply an array</p>