title: How to get a CCITT-CRC16 on Python's crcmod lybrary?
body: <p>I'm having problems to make a code in Python 3.4 using the CRCMOD library to get the CCITT CRC16 check.</p>
  
  <p>Thats my string:</p>
  
  <pre><code>a731986b1500087f9206e82e3829fe8bcffed5555efd00a100980000010000000100000009010013bb1d001e287107009b3000000300000088330000f427500077026309
  </code></pre>
  
  <p>The spected crc value is <strong>1d7f</strong></p>
  
  <p>My code:</p>
  
  <pre><code>import crcmod
  
  crc16 = crcmod.mkCrcFun(0x11021, 0x1d0f, False, 0x0000)
  
  hex(crc16(b'a731986b1500087f9206e82e3829fe8bcffed5555efd00a100980000010000000100000009010013bb1d001e287107009b3000000300000088330000f427500077026309'))
  </code></pre>
  
  <p>It returns: <strong>7d67</strong></p>
  
  <p>What am I doing wrong?</p>