struct packet {
	unsigned char ops;
	unsigned short int id;
	unsigned short int flags;
	unsigned int assoc;
} __attribute__((__packed__));
typedef struct packet packet;

struct data_assoc {
	unsigned short int len;
	unsigned char buf[0];
} __attribute__((__packed__));
typedef struct data_assoc data_assoc;

class Packet(object):
    def __init__(self, ops=None, id=None, flags=None, assoc=None, bytes=None):
        self.ops = ops
        self.id = id
        self.flags = flags
        self.assoc = assoc
        if bytes:
            self.fromBytes(bytes)

    def fromBytes(self, bytes):
        # little-endian
        (self.ops, self.id, self.flags, self.assoc) = struct.unpack("<BHHI", bytes)

    def toBytes(self):
        # little-endian
        return struct.pack("<BHHI", self.ops, self.id, self.flags, self.assoc)

    def __len__(self):
        return struct.calcsize("<BHHI")

    def __repr__(self):
        return "ops %d, id %d, flags %d, assoc %d " % (self.ops, self.id, self.flags, self.assoc)

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        input = raw_input("ops, id, flags, assoc: ")
        [ops, id, flags, assoc] = input.split(",")
        header = Header(int(ops.strip()), int(id.strip()), int(flags.strip()), int(assoc.strip())) 
        p_out = Packet(header)
        sock.sendto(p_out.toBytes(), ADDR) # hit breakpoint
        data, addr = sock.recvfrom(PKTSIZE)
        p_in = Packet(bytes=data)        
        print repr(p_in)
        sock.close()

drifter3@games $ ./level3.py
out = ops, id, flags, assoc: 0,0,0,0
in = ops 0, id 0, flags 1, assoc 3696333875