Real Python: Socket Programming in Python (Guide)

Socket programming is crucial for network communication, allowing data exchange between devices. Python's socket module provides an interface to the Berkeley sockets API, enabling inter-process communication over networks. This tutorial covers creating socket servers and clients, handling multiple connections, and managing errors in Python's socket module. By the end of this tutorial, you'll understand that a socket in Python is an endpoint for sending or receiving data across a network using the socket API. Socket programming in Python involves using sockets to establish communication between a server and clients over a network. A simple echo server can be created using sockets to listen for client connections and echo back received messages. Handling multiple clients with Python sockets can be achieved using non-blocking sockets and the selectors module for concurrent connections. Connection errors in socket programs in Python can be managed by implementing error handling and using exceptions like OSError. The Transmission Control Protocol (TCP) is a reliable protocol that ensures packets dropped in the network are detected and retransmitted by the sender, and data is read by your application in the order it was written by the sender. In contrast, User Datagram Protocol (UDP) sockets created with socket.SOCK_DGRAM aren't reliable, and data read by the receiver can be out-of-order from the sender's writes. Networks are a best-effort delivery system, and TCP relieves you from having to worry about packet loss, out-of-order data arrival, and other pitfalls that invariably happen when communicating across a network.