Python--network programming-----socket based on UDP protocol

Server:

 1 from socket import *
 2 
 3 server = socket(AF_INET, SOCK_DGRAM)
 4 server.bind(('127.0.0.1', 8080))
 5 
 6 while True:
 7     data, client_addr = server.recvfrom(1024)
 8     print(data, client_addr)
 9 
10     server.sendto(data.upper(), client_addr)
11 
12 server.close()

 

Client:

 1 from socket import *
 2 
 3 client = socket(AF_INET, SOCK_DGRAM)
 4 
 5 while True:
 6     msg = input(">>:").strip()
 7     client.sendto(msg.encode('utf-8'), ('127.0.0.1', 8080))
 8 
 9     data, server_addr = client.recvfrom(1024)
10     print(data, server_addr)
11 
12 client.close()

Start the server first, then start the client, enter the lowercase letters abc on the client,

The client running result is:

1 >>:abc
2 b'ABC' ('127.0.0.1', 8080)
3 >>:

The result of running the server is:

1 b'abc' ('127.0.0.1', 55255)

This implements a simple socket program based on the udp protocol

 

Sockets based on the udp protocol can send nulls:

Enter empty on the client side,

The client running result is:

1 >>:
2 b'' ('127.0.0.1', 8080)
3 >>:
4 b'' ('127.0.0.1', 8080)
5 >>:

Even if the data sent by udp is empty, udp is a datagram protocol, and the datagram also contains ip port information, so the datagram is not empty.