I'm planning to design a server that receives data from multiple clients, the server don't need to send anything back to the client, though STATUS_OK is still cool but not necessary.
I know the basics of Python socket module, twisted framework but my question is,  should i use UDP or TCP? The client that need to stay connected at all.
I hope you guys understand my question, thank you for your wonderful help here
I would use TCP in your situation, but it's hard to tell what the specifics of your needs are. TCP is in most cases a better protocol because it's much more reliable. Data is very rarely lost in TCP, however this does slow it down a bit. Since you're not sending anything back to the client, the fact that TCP is a streaming protocol shouldn't really matter too much.
So I'd just go with TCP.
Python Socket programming (TCP vs. UDP)