def get_packet(in_data): valid_packet = False packet = None if in_data != b'': header = get_header(in_data) checksum = header[1] pac_type = header[2] seq_no = header[3] data_len = header[4] if data_len >= len(in_data) - 20: data = get_data(in_data, data_len) packet = Packet(pac_type, seq_no, data_len, data, checksum) valid_packet = packet.checksum == packet.calculate_checksum() return packet, valid_packet