Python server programming: network sockets explained in detail

Network programming in Python can be implemented using sockets. Sockets are a basic component of network communication and a universal computer network programming interface. The socket library in Python provides a simple yet powerful interface to support data transfer, which provides good support for Python server programming.

A socket is the two endpoints of a communication link and is used to implement network communication. It provides a data transmission interface between computers. In Python, a Socket handle can be a client connection request or a server listening request. Sockets can be used for both TCP and UDP protocols.

In Python, sockets are divided into two types:

1. TCP socket

TCP socket provides a The connection transmission method. The client needs to establish a connection when connecting to the server. The connection process is a "three-way handshake" process. The TCP protocol will detect a series of issues such as whether the transmission is completed and retransmission if the transmission fails. TCP socket transmission efficiency is low, but data transmission is reliable.

2. UDP socket

UDP socket provides a "connectionless" method, which does not require a "three-way handshake", compared to TCP socket The interface efficiency is high, but the transmission reliability is low.

In Python, when using a socket, a connection needs to be established first. After the connection is completed, data needs to be transmitted. After the transmission is completed, the connection needs to be closed. The following is the server-side socket implementation in Python:

import socket

HOST = '127.0.0.1' #本地ip
PORT = 8888 #端口号

#创建一个套接字对象
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

#将套接字与本地ip及其端口号绑定
server.bind((HOST, PORT))

#开始监听传入的连接
server.listen()

#不断接收客户端的连接，如果有新的连接加入，就创建新的连接线程进行处理
while True:
    #获取客户端请求
    conn, addr = server.accept()
    print('Connected by', addr)

    #接收客户端发来的数据并回应
    data = conn.recv(1024)
    print(data)
    conn.sendall(data)

    #关闭连接
    conn.close()

The above is a simple example code for the Python server-side socket implementation. The following is a brief introduction to the functions and implementation methods of each part of the code.

First, you need to import the Python socket library socket, and then declare the local IP address and port number of the server. You can set this later by yourself, as long as it does not conflict with other services opened on the computer. .

In the code, an empty socket object server is first established, which is completed using the socket.socket function. The first parameter AF_INET represents the IPv4 protocol, and the second parameter SOCK_STREAM represents the use of the TCP protocol. .

Next, use the bind function to bind the socket server to the local IP and its corresponding port number. Here, the tuple form is used, and the local IP and port number are passed in as parameters. Pay attention to the IP address. Use single quotes.

After that, start the listening of the socket server and use the listen function. In this example, the server will receive the socket information corresponding to the local IP and port number, accept the connection request, and return a connection success message.

Finally, use a loop to continuously monitor the client's request, get one request each time, print out the IP address of the connected client, then receive the data sent by the client, print it out, and send a response . After completing the data transfer, close the connection.

Using Socket sockets for network programming in Python will give you a greater degree of freedom and facilitate and flexibly implement various network communication-based applications. Here is a brief introduction to Python server-side sockets. The implementation method, I hope it will be helpful to you.

The above is the detailed content of Python server programming: network sockets explained in detail. For more information, please follow other related articles on the PHP Chinese website!