Django 1.0 Website Development: Build powerful web applications, quickly and cleanly, with the Django application framework

Web development has made great progress during the last few years. It began as a tedious task that involved using a protocol called Common Gateway Interface (CGI) for interfacing external programs with the web server. The CGI applications used standard I/O facilities available to the C programming language in order to manually parse user input and produce page output. In addition to being difficult to work with, CGI required a separate copy of the program to be launched for each request. This used to quickly overwhelm servers.

Next, scripting languages were introduced to web development, and this inspired developers to create more efficient technologies. Languages such as Perl and PHP quickly made their way into the world of web development. As a result, common web tasks such as cookie handling, session management, and text processing became much easier. Although scripting languages included libraries to deal with day-to-day web-related tasks, they lacked unified frameworks, as libraries were usually disparate in design, usage, and conventions. Therefore, the need for cohesive frameworks arose.

A few years ago, the model-view-controller (MVC) pattern for web-based applications was introduced. This software engineering pattern separates data (model), user interface (view), and data-handling logic (controller) so that one can be changed without affecting the others. The benefits of this pattern are obvious. With it, designers can work on the interface without worrying about data storage or management. Developers are able to program the logic of data handling without getting into the details of presentation. As a result, the MVC pattern quickly found its way into web languages, and serious web developers started to embrace it in preference to previous techniques.

The following diagram illustrates how each of the components of the MVC pattern interacts with each other to serve a user request:

Python is a general purpose programming language. Although it is used for a wide variety of applications, Python is very suitable for developing web applications. It has a clean and elegant syntax. It is supported by a large library of standard and contributed modules, which covers everything from multi-threading to the zipping of files. The language's object-oriented model is especially suited for MVC style development.

Sooner or later, performance will become a major concern with web projects. Python's runtime environment shines here, as it is known to be fast and stable. Python supports a wide range of web servers through modules, including the famous Apache. Furthermore, it is available for all the major platforms: UNIX/Linux, Windows, and Mac. Python also supports a wide array of database servers, but you won't have to deal directly with them. Django provides a unified layer of access to all available database engines, as we will see later.

Python is a free software that you can download and freely use from http://python.org/. You are even allowed to distribute it without having to pay any fees. Access to the source code is available to those who want to add features or fix bugs. As a result, Python enjoys a large community of developers who quickly fix bugs and introduce new features.

Python is very easy to learn, and it is being adopted in many universities as the first programming language to be taught. Although this book assumes working knowledge of Python, advanced features will be explained as they are used. If you want to refresh your Python knowledge, you are recommended to read the official Python tutorial available at http://python.org/doc/ before continuing with this book.

To sum up, Python was chosen over many other scripting languages for this book. The reasons are:

Since the spread of the MVC pattern into web development, Python has provided quite a few choices when it comes to web frameworks such as Django, TurboGears, and Zope. Although choosing one out of many can be confusing initially, having several competing frameworks can only be a good thing for the Python community. That's because it drives the development of all the frameworks further and provides a rich set of options to choose from.

Django is one of the available frameworks for Python, so the question is: What sets it apart to become the topic of this book, and what makes it popular in the Python community? The next subsections will answer these questions by providing an overview of the main advantages of Django.

Django started as an internal project at the Lawrence Journal-World newspaper in 2003. Often, the web development team there had to implement new features or even entire applications within hours. Therefore, Django was created to meet the fast deadlines of journalism web sites, while at the same time keeping the development process clean and maintainable. By the summer of 2005, Django became mature enough to handle several high-traffic sites, and the developers decided to release it to the public as an open source project. The project was named after the jazz guitarist, Django Reinhardt.

Now that Django is an open source project, it has gathered developers and users from all over the world. Bug fixes and new features are introduced on a daily basis, and the original development team keeps an eye on the whole process to make sure that Django remains what it is meant to be—a web framework for building clean, maintainable, and reusable web applications.

Web development has made large leaps of progress over the last few years. The advent of scripting languages, web frameworks, and AJAX made rapid development of web applications possible and easier than ever. This book takes you through a tutorial for building a Web 2.0 application using two hot technologies: Python and Django. The application allows users to store and share bookmarks. Many of the exciting Web 2.0 applications will be explained and developed throughout this book.

In the next chapter, we will set up our development environment by installing the necessary software, and get a feel for Django by creating our first application.