Django 4. Practice of Creating Websites in Python

The book is dedicated to the development of websites in the Python language using the Django web framework. It presents the innovations of Django 4 and gives a complete description of its tools: models, controllers, templates, means of processing user input,... including uploaded files, access restrictions, middleware, signals, tools for sending emails, caching, etc. Additional libraries are discussed, which process BBCode, CAPTCHA, display graphic thumbnails, authenticate via social networks (in particular, “VKontakte”), and integrate with Bootstrap. It covers programming REST web services, using and configuring the Django admin website, publishing sites with the Uvicorn web server, working with PostgreSQL databases, localizing strings, formats, and time zones. A detailed description of creating a fully functional website — an electronic bulletin board — is provided. The electronic archive application on the publishing website contains codes for all examples. What is a web framework? A framework (from English framework — framework) is a software library that implements most of the standard functionality of the developed product. In other words, it is, in the full sense of the word, a framework, on which the developer of a specific product 'hangs' their nodes, mechanisms, and decorative details. A web framework is a framework for programming websites. Typically, it provides the following standard functionalities: •database interaction — through unified tools, independent of a specific DBMS; •processing client requests — in particular, determining which page is requested; •generating requested web pages based on templates; •access restriction — allowing only registered users to access closed pages and only after they have logged in; •processing data entered by visitors into web forms — in particular, validating their correctness; •receiving and saving files uploaded by users; •sending emails; •caching generated pages on the server side — to improve performance; •localization — translating the site into other languages! Attention! The author assumes that readers of this book are familiar with HTML, CSS, JavaScript, Python, the principles of DBMS operation, and have basic skills in web development. These topics will not be covered in the book.