This book is aimed at developers who want insights on building highly maintainable websites using Django. It helps you gain a deeper understanding of not just the framework but also familiarizes you with several web development concepts.

It will be useful for beginners and experienced Django developers alike. It assumes that you are fluent in Python and have completed a basic tutorial on Django (try the official polls tutorial or a video tutorial from my website—arunrocks.com).

You do not have to be an expert in Django or Python. No prior knowledge of patterns is expected, but it would be helpful. Once again, this book is not about the classic Gang of Four patterns.

A lot of practical advice here might not be unique to just Django, but to most kinds of web development. By the end of this book, you should be a more efficient and pragmatic web developer.

Chapter 1, Django and Patterns, helps us understand Django better by telling us why it was created and how it has evolved over time. Then, it introduces design patterns, their importance, and several popular pattern collections.

Chapter 2, Application Design, guides us through the early stages of an application's life cycle, such as gathering requirements and creating mock-ups. We will also see how to break your project into modular apps through our running example—SuperBook.

Chapter 3, Models, gives us insights into how models can be graphically represented, structured using several kinds of patterns and can be later altered using migrations.

Chapter 4, Views and URLs, shows us how function-based views evolved into class-based views with the powerful mixin concept, familiarizes us with useful view patterns, and teaches how short and meaningful URLs are designed.

Chapter 5, Templates, walks us through Django template language constructs, explaining its design choices, suggests how to organize template files, introduces handy template patterns, and points to several ways Bootstrap can be integrated and customized.

Chapter 6, Admin Interface, focuses on how to use Django's brilliant out-of-the box admin interface more effectively and several ways to customize it, from enhancing the models to toggling feature flags.

Chapter 7, Forms, illustrates the often confusing form workflow, different ways of rendering forms, improving a form's appearance using crispy forms, and various applied form patterns.

Chapter 8, Working Asynchronously, tours various asynchronous solutions for the Django developer, from the feature-rich Celery task queues, Python 3's asyncio, to the brand new Channels, and compares them for you.

Chapter 9, Creating APIs, explains RESTful API design concepts with practical advice on topics such as versioning, error handling, and design patterns using the Django REST framework.

Chapter 10, Dealing with Legacy Code, tackles common issues with legacy Django projects, such as identifying the right version, locating the files, where to start reading a large code base, and how to enhance it to add new functionality.

Chapter 11, Testing and Debugging, gives us an overview of various testing and debugging tools and techniques, introducing test-driven development, mocking, logging, and debuggers.

Chapter 12, Security, familiarizes you with various web security threats and their counter measures, specifically looking at how Django can protect you. Finally, a handy security checklist reminds you of the commonly overlooked areas.

Chapter 13, Production-Ready, is a crash course in deploying a public-facing application beginning with choosing your webstack, understanding hosting options, and walking through a typical deployment process. We go into the details of monitoring and performance at this stage.

Appendix A, Python 2 Versus Python 3, introduces Python 3 to Python 2 developers. Starting off by showing the most relevant differences while working in Django, we move on to the new modules and tools offered in Python 3.

You will just need a computer (PC or Mac) and internet connectivity to start with. Then, ensure that the following are installed:

I recommend working on a Linux-based system such as Ubuntu or Arch Linux. If you are on Windows, you can work on a Linux virtual machine using Vagrant or VirtualBox. Full disclosure, I prefer command-line interfaces, Emacs, and eggs sunny side up.

Certain chapters might also require installing certain Python libraries or Django packages. They will be mentioned like this—the factory_boy package. They can be installed using pip like this:

$ pip install factory_boy

Hence, it is highly recommended that you first create a separate virtual environment, as mentioned in Chapter 2, Application Design.

from django.db import models
class SuperHero(models.Model):
    name = models.CharField(max_length=100)

name = request.GET['user'] 

sql = "SELECT email FROM users WHERE username = '{}';".format(name) 

$ django-admin.py --version
1.6.1

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