text: import socketserver
  
  
  def crc16(s):
      crcValue = 0xffff
      check_error = 0x8cdd
      crc16tab = (
      0x0000, 0x1189, 0x2312, 0x329B, 0x4624, 0x57AD, 0x6536, 0x74BF,
      0x8C48, 0x9DC1, 0xAF5A, 0xBED3, 0xCA6C, 0xDBE5, 0xE97E, 0xF8F7,
      0x1081, 0x0108, 0x3393, 0x221A, 0x56A5, 0x472C, 0x75B7, 0x643E,
      0x9CC9, 0x8D40, 0xBFDB, 0xAE52, 0xDAED, 0xCB64, 0xF9FF, 0xE876,
      0x2102, 0x308B, 0x0210, 0x1399, 0x6726, 0x76AF, 0x4434, 0x55BD,
      0xAD4A, 0xBCC3, 0x8E58, 0x9FD1, 0xEB6E, 0xFAE7, 0xC87C, 0xD9F5,
      0x3183, 0x200A, 0x1291, 0x0318, 0x77A7, 0x662E, 0x54B5, 0x453C,
      0xBDCB, 0xAC42, 0x9ED9, 0x8F50, 0xFBEF, 0xEA66, 0xD8FD, 0xC974,
      0x4204, 0x538D, 0x6116, 0x709F, 0x0420, 0x15A9, 0x2732, 0x36BB,
      0xCE4C, 0xDFC5, 0xED5E, 0xFCD7, 0x8868, 0x99E1, 0xAB7A, 0xBAF3,
      0x5285, 0x430C, 0x7197, 0x601E, 0x14A1, 0x0528, 0x37B3, 0x263A,
      0xDECD, 0xCF44, 0xFDDF, 0xEC56, 0x98E9, 0x8960, 0xBBFB, 0xAA72,
      0x6306, 0x728F, 0x4014, 0x519D, 0x2522, 0x34AB, 0x0630, 0x17B9,
      0xEF4E, 0xFEC7, 0xCC5C, 0xDDD5, 0xA96A, 0xB8E3, 0x8A78, 0x9BF1,
      0x7387, 0x620E, 0x5095, 0x411C, 0x35A3, 0x242A, 0x16B1, 0x0738,
      0xFFCF, 0xEE46, 0xDCDD, 0xCD54, 0xB9EB, 0xA862, 0x9AF9, 0x8B70,
      0x8408, 0x9581, 0xA71A, 0xB693, 0xC22C, 0xD3A5, 0xE13E, 0xF0B7,
      0x0840, 0x19C9, 0x2B52, 0x3ADB, 0x4E64, 0x5FED, 0x6D76, 0x7CFF,
      0x9489, 0x8500, 0xB79B, 0xA612, 0xD2AD, 0xC324, 0xF1BF, 0xE036,
      0x18C1, 0x0948, 0x3BD3, 0x2A5A, 0x5EE5, 0x4F6C, 0x7DF7, 0x6C7E,
      0xA50A, 0xB483, 0x8618, 0x9791, 0xE32E, 0xF2A7, 0xC03C, 0xD1B5,
      0x2942, 0x38CB, 0x0A50, 0x1BD9, 0x6F66, 0x7EEF, 0x4C74, 0x5DFD,
      0xB58B, 0xA402, 0x9699, 0x8710, 0xF3AF, 0xE226, 0xD0BD, 0xC134,
      0x39C3, 0x284A, 0x1AD1, 0x0B58, 0x7FE7, 0x6E6E, 0x5CF5, 0x4D7C,
      0xC60C, 0xD785, 0xE51E, 0xF497, 0x8028, 0x91A1, 0xA33A, 0xB2B3,
      0x4A44, 0x5BCD, 0x6956, 0x78DF, 0x0C60, 0x1DE9, 0x2F72, 0x3EFB,
      0xD68D, 0xC704, 0xF59F, 0xE416, 0x90A9, 0x8120, 0xB3BB, 0xA232,
      0x5AC5, 0x4B4C, 0x79D7, 0x685E, 0x1CE1, 0x0D68, 0x3FF3, 0x2E7A,
      0xE70E, 0xF687, 0xC41C, 0xD595, 0xA12A, 0xB0A3, 0x8238, 0x93B1,
      0x6B46, 0x7ACF, 0x4854, 0x59DD, 0x2D62, 0x3CEB, 0x0E70, 0x1FF9,
      0xF78F, 0xE606, 0xD49D, 0xC514, 0xB1AB, 0xA022, 0x92B9, 0x8330,
      0x7BC7, 0x6A4E, 0x58D5, 0x495C, 0x3DE3, 0x2C6A, 0x1EF1, 0x0F78,
      )
      tam = len(s)/2
      for ch in s:
          tmp=crcValue^(ch)
          #print '%s - TMP - %s' % (hex(crcValue), hex(tmp)) # debug
          crcValue=(crcValue >> 8)^crc16tab[(tmp & 0xff)]
          # crc = (crc >>> 8) ^ table[(crc ^ b) & 0xff];
      return crcValue
  
  class MyTCPHandler(socketserver.BaseRequestHandler):
      def handle(self):
          self.data = self.request.recv(1024).strip()
          print("{} wrote:".format(self.client_address[0]))
          print(self.data)
  
          if self.data[0] == 0x78 and self.data[1] == 0x78:
  
              inte = [int(i) for i in self.data]
              hexa = [hex(i) for i in self.data]
  
              packet_len = self.data[2]
              prot_num = self.data[3]
  
              info = self.data[4: 4 + packet_len - 5]
              info_int = [int(i) for i in info]
  
              serial_n = self.data[4 + packet_len - 5 : 4 + packet_len - 5 + 2]
  
              error_byte = self.data[2:4 + packet_len - 5 + 2]
              check = crc16(error_byte)
  
              error_check = self.data[4 + packet_len - 5 + 2 : 4 + packet_len - 5 + 2 + 2]
  
              print("check:", check, "error check:", error_check)
  
              stop_bit = self.data[4 + packet_len - 5 + 2 + 2 : 4 + packet_len - 5 + 2 + 2 + 2]  # 0x0D 0x0A
              if stop_bit != [0x0D,0x0A]:
                  print("Wrong stop bit")
                  # return
  
              if prot_num == 0x01:
                  print("login")
                  self.request.send(b"\x78\x78\x05\x01\x00\x01\xD9\xDC\x0D\x0A")
              elif prot_num == 0x12:
                  print("location")
              elif prot_num == 0x13:
                  print("status info")
              elif prot_num == 0x15:
                  print("string info")
              elif prot_num == 0x16:
                  print("alarm data")
              elif prot_num == 0x1A:
                  print("GPS")
              elif prot_num == 0x80:
                  print("command info")
              else:
                  print("unknown type")
                  return
  
          else:
              print("Wrong start bit")
              return
  
  
  
  HOST, PORT= "0.0.0.0", 8085
  server = socketserver.TCPServer((HOST, PORT), MyTCPHandler)
  try:
      server.serve_forever()
  except:
      server.server_close()