title: xor all data in packet
body: <p>I need a small program that can calculate the checksum from a user input.</p>
  
  <p>Unfortunately, all I know about the checksum is that it's xor all data in packet.</p>
  
  <p>I have tried to search the net for an example without any luck.</p>
  
  <p>I know if I have a string: 41,4D,02,41,21,04,02,02,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00</p>
  
  <p>This should result in a checksum of 6A.</p>
  
  <p>Hopefully someone could help me. If someone has an example writen in Python 3, could also work for me</p>