Understanding Web Communication
Explore how Python programs communicate with remote servers using the HTTP client-server model. Understand the request-response cycle with GET and POST methods, interpret HTTP status codes, and work with JSON to handle data exchanged over the web. This lesson prepares you to build Python applications that retrieve and send data securely from external APIs.
So far, our Python programs have operated only on local resources. They run locally, process local data, and produce output on the console. However, modern software is rarely self-contained. Most applications rely on communication between distributed systems. For example, a stock ticker retrieves real-time market data, a weather dashboard queries forecasting services, and a chatbot interacts with external APIs. In each case, the program must exchange data with remote servers. To support this communication, we need to understand HTTP, the protocol used for data exchange on the web.
In this lesson, we examine the request–response process that occurs whenever a web page loads or an application communicates with a server, and learn how to perform the same interaction programmatically.
The client-server relationship
The web is not a shapeless cloud; it is a structured network built on a strict relationship known as the client-server model. Every interaction on the web divides participants into two distinct roles:
The client: This is the entity that initiates communication by requesting a resource or service. In everyday ...