15.1 The HTTP request-response model

The HTTP protocol is nearly stateless: a user agent (or browser) makes a request and the server provides a response. For services that don’t involve cookies, a client application can take a functional view of the protocol. We can build a client using the http.client or urllib.request module. An HTTP user agent can be implemented as a function like the following:

import urllib.request 
 
def urllib_get(url: str) -> tuple[int, str]: 
    with urllib.request.urlopen(url) as response: 
        body_bytes = response.read() 
        encoding = response.headers.get_content_charset("utf-8") 
        return response.status, body_bytes.decode(encoding)

A program like wget or curl does this kind of processing using a URL supplied as a command-line argument. A browser does...