title: Validating the checksum using binascii.crc32()
body: <p>I am sending multiple messages from an MCU to my computer and I want to use a 32-bit Cyclic Redundancy Check to verify that the messages are correct. From what I've read, it should be possible to append the CRC remainder to the last message and run that through the CRC function. If the message was error free, it should then return zero (am I right?)
  I have however been unsuccessful in implementing this using the binascii library function <a href="https://docs.python.org/3/library/binascii.html#binascii.crc32" rel="nofollow">binascii.crc32()</a>.</p>
  
  <p>Let's for example say I want to check the message internally from the example given in Python docs (I'm using Python 3.5). How would I go ahead checking if the message is error free (which of course it is in this example)?</p>
  
  <pre><code>crc = binascii.crc32(b"hello")
  crc = binascii.crc32(b" world", crc)
  
  check_for_error() # &lt;--- ?
  </code></pre>