Mock it Til’ You Make It: Test Django with mock and httpretty

The tutorial covers how to use Python's mock and httpretty libraries to test Django app parts that communicate with external services. It uses a simple Django app called "Hacker News Hotline" to fetch today's headlines from Hacker News and serve them behind a TwiML endpoint, allowing anyone calling the Twilio number to hear the latest headlines on Hacker News. The tutorial also introduces Django's RequestFactory class and how it can be used to test Django views without making actual HTTP requests.