Someone

class Chat(packet):
	def __init__(self):
		packet.__init__(self,"C","s","*")

	#data should be username:message
        def pack(self,data):
                type = self.type
                size = pack("i",len(data))
                data = pack(str(len(data)) + self.format, data)
                packet = type + size + data
		return packet

	def unpack(self,data,size):
		return unpack(str(size) + self.format, data)[0]

	def execute(self,data):
		print data