Web Development with Django: A definitive guide to building modern Python web applications using Django 4. 2 Ed

Cover....1

Title Page....2

Copyright and Credits....3

Dedication....4

Contributors....5

Table of Contents....8

Preface....18

Chapter 1: Introduction to Django....24

Technical requirements....25

Scaffolding a Django project and app....25

Exercise 1.01 – creating a project and app, and starting the development server ....27

Understanding the model-view-template paradigm....30

Models....30

Views....31

Templates....31

MVT in practice....31

An introduction to HTTP....34

Processing a request....38

Exploring the Django project structure....39

The myproject directory....41

Django development server....42

Django apps....42

PyCharm setup....44

Exercise 1.02 – project setup in PyCharm....44

Introducing Django views....53

Exploring URL mapping detail....54

Exercise 1.03 – writing a view and mapping a URL to it....55

Working with GET, POST, and QueryDict objects....59

Exercise 1.04 – exploring GET values and QueryDict objects....61

Exploring Django settings....63

Referring to Django Settings in Your Code....65

Finding HTML templates in app directories....66

Exercise 1.05 – creating a templates directory and a base template....66

Rendering a template with the render function....70

Exercise 1.06 – rendering a template in a view....70

Rendering variables in templates....72

Exercise 1.07 – using variables in templates....72

Debugging and dealing with errors....75

Exceptions....75

Exercise 1.08 – generating and viewing exceptions....77

Debugging....78

Exercise 1.09 – debugging your code....79

Activity 1.01 – creating a site welcome screen....83

Activity 1.02 – a book search scaffold....84

Summary....86

Chapter 2: Models and Migrations....88

Technical requirements....89

Understanding and using databases....89

Relational databases....90

Non-relational databases....90

Database operations using SQL....91

Data types in relational databases....91

Exercise 2.01 – creating a book database....91

Understanding CRUD operations using SQL....95

SQL create operations....96

SQL read operations....96

SQL update operations....97

SQL delete Operations....98

Exploring Django ORM....98

Database configuration and creating Django applications....99

Django apps....100

Django migration....101

Creating Django models and migrations....103

Field options....105

Primary keys....107

Relationships....109

Adding the Review model....113

Model methods....115

Migrating the reviews app....116

Django’s database CRUD operations....118

Exercise 2.02 – creating an entry in the bookr database....119

Exercise 2.03 – using the create() method to create an entry....120

Creating an object with a foreign key....121

Exercise 2.04 – creating records for a many-to-one relationship....121

Exercise 2.05 – creating records with many-to-many relationships....123

Exercise 2.06 – a many-to-many relationship using the add() method....124

Using the create() and set() methods for many-to-many relationships....125

Read operations....126

Exercise 2.07 – using the get() method to retrieve an object....126

Returning an object using the get() method....127

Exercise 2.08 – using the all() method to retrieve a set of objects....128

Retrieving objects by filtering....128

Exercise 2.09 – using the filter() method to retrieve objects....129

Filtering by field lookups....129

Using pattern matching for filtering operations....130

Retrieving objects by using the exclude() method....131

Retrieving objects using the order_by() method....131

Querying across relationships....134

Querying using foreign keys....134

Querying using the model name....134

Querying across foreign key relationships using the object instance....135

Exercise 2.10 – querying across a many-to-many relationship using the field lookup....135

Exercise 2.11 – a many-to-many query using objects....136

Exercise 2.12 – a many-to-many query using the set() method....136

Exercise 2.13 – using the update() method....137

Exercise 2.14 – using the delete() method....138

Bulk create and bulk update operations....138

Exercise 2.15 – creating multiple records using bulk_create....139

Exercise 2.16 – updating multiple records using bulk_update....140

Performing complex lookups using Q objects....140

Exercise 2.17 – performing a complex query using a Q object....141

Exercise 2.18 – verifying whether a queryset contains a given object....141

Activity 2.01 – creating models for a project management application....143

Populating the Bookr project’s database....143

Summary....144

Chapter 3: URL Mapping, Views, and Templates....146

Technical requirements....147

Understanding function-based views....147

Understanding class-based views....147

URL configuration....148

Exercise 3.01 – implementing a simple function-based view....150

Working with Django templates....153

Exercise 3.02 – using templates to display a greeting message....155

Django’s template language....157

Exercise 3.03 – displaying a list of books and reviews....159

Template inheritance....162

Template styling with Bootstrap....163

Exercise 3.04 – adding template inheritance and a Bootstrap navigation bar....165

Activity 3.01 – implementing the book details view....167

Summary....169

Chapter 4: An Introduction to Django Admin....170

Technical requirements....172

Creating a superuser account....172

Exercise 4.01 – creating a superuser account....172

CRUD operations using the Django admin app....174

Create....175

Retrieve....177

Update....179

Delete....181

Managing Django users and groups....182

Exercise 4.02 – adding and modifying users and groups through the admin app....183

Registering models with the admin app....188

Registering the reviews model....189

Change lists....190

The Change publisher page....191

The Book change page....195

Exercise 4.03 – foreign keys and deletion behavior in the admin app....198

Customizing the admin interface....200

Site-wide Django admin customizations....200

Customizing the ModelAdmin classes....210

The list display fields....211

The display decorator....217

The filter....218

Exercise 4.04 – adding the date list_filter and date_hierarchy filters....219

The search bar....222

Excluding and grouping fields....225

Activity 4.03 – customizing the Model admins....229

Summary....232

Chapter 5: Serving Static Files....234

Technical requirements....236

Static file serving....236

Introduction to Static Files Finder....237

Static file finders – use during a request....238

AppDirectoriesFinder....238

Static file namespacing....239

Exercise 5.01 – serving a file from an app directory....241

Generating static URLs with the static template tag....245

Exercise 5.02 – using the static template tag....249

FileSystemFinder....252

Exercise 5.03 – serving from a project static directory....253

Static file finders – use during collectstatic....256

Exercise 5.04 – collecting static files for production....258

STATICFILES_DIRS prefixed mode....259

The findstatic command....262

Exercise 5.05 – finding files using findstatic....263

Serving the latest files (for cache invalidation)....266

Exercise 5.06 – exploring the ManifestFilesStorage storage engine....268

Custom storage engines....272

Activity 5.01 – adding a Reviews logo....275

Activity 5.02 – CSS enhancements....277

Activity 5.03 – adding a global logo....279

Summary....281

Chapter 6: Forms....282

Technical requirements....282

What is a form?....283

The form element....285

Types of inputs....286

Exercise 6.01 – building a form in HTML....287

Form security with Cross-Site Request Forgery Protection....295

Accessing data in the View....299

Exercise 6.02 – working with POST data in a view....299

Choosing between GET or POST....303

Why use GET when we can put parameters in the URL mappings?....305

The Django Forms library....306

Defining a form....307

Rendering a form in a template....318

Exercise 6.03 – building and rendering a Django form....323

Validating forms and retrieving Python values....328

Exercise 6.04 – validating forms in a view....331

Built-in field validation....334

Exercise 6.05 – adding extra field validation....335

Activity 1 – Book Search....337

Summary....341

Chapter 7: Advanced Form Validation and Model Forms....342

Technical requirements....343

Custom field validation and cleaning....343

Custom validators....343

Cleaning methods....345

Multi-field validation....346

Exercise 7.01 – custom clean and validation methods....350

Adding placeholders and initial values....359

Exercise 7.02 – placeholders and initial values....361

Creating or editing Django models....363

The ModelForm class....365

Exercise 7.03 – creating and editing a publisher....369

Activity 7.01 – styling and integrating the publisher form....375

Activity 7.02 – Review Creation UI....379

Summary....386

Chapter 8: Media Serving and File Uploads....388

Technical requirements....389

Settings for media uploads and serving....389

Serving media files in development....389

Exercise 8.01 – configuring media storage and serving....390

Context processors and using MEDIA_URL in templates....394

Exercise 8.02 – template settings and using MEDIA_URL in templates....396

File uploads using HTML forms....399

Working with uploaded files in a view....401

Exercise 8.03 – file upload and download....404

File uploads with Django forms....408

Exercise 8.04 – file uploads with a Django form....409

Image uploads with Django forms....414

Resizing an image with Pillow....416

Exercise 8.05 – image uploads using Django forms....417

Serving uploaded (and other) files using Django....420

Storing files on model instances....421

Storing images on model instances....425

Working with FieldFile....426

Referring to media in templates....431

ModelForms and file uploads....437

Exercise 8.07 – file and image uploads using ModelForm....439

Handling file saving....442

Activity 8.01 – image and PDF upload of books....444

Activity 8.02 – displaying the cover and sample link....448

Summary....450

Chapter 9: Sessions and Authentication....452

Technical requirements....453

Middleware....453

Middleware modules....454

Implementing authentication views and templates....456

Exercise 9.01 – repurposing the Admin app login template....461

Password storage in Django....464

The profile page and the request.user object....464

Exercise 9.02 – adding a profile page....465

Authentication decorators and redirection....467

Exercise 9.03 – adding authentication decorators to the views....470

Enhancing templates with authentication data....473

Exercise 9.04 – toggling login and logout links in the base template ....473

Activity 9.01 – authentication-based content using conditional blocks in templates ....475

Sessions....477

The session engine....477

Do you need to flag cookie content?....478

Pickle or JSON storage?....479

Exercise 9.05 – examining the session key....480

Storing data in sessions....484

Exercise 9.06 – storing recently viewed books in sessions....485

Activity 9.02 – using session storage for the Book Search page....490

Summary....492

Chapter 10: Advanced Django Admin and Customizations....494

Technical requirements....495

Customizing the admin site....495

Discovering admin files in Django....495

Django’s AdminSite class....496

Exercise 10.01 – creating a custom admin site for Bookr....498

Overriding the default admin.site....501

Exercise 10.02 – overriding the default admin site....501

Customizing admin site text using AdminSite attributes....503

Customizing admin site templates....504

Exercise 10.03 – customizing the logout template for the Bookr admin site....506

Adding views to the admin site....508

Creating the view function....508

Accessing common template variables....509

Mapping URLs for the custom view....509

Restricting custom views to the admin site....510

Exercise 10.04 – adding custom views to the admin site....511

Passing additional keys to templates using template variables....514

Activity 10.01 – building a custom admin dashboard with a built-in search....515

Summary....517

Chapter 11: Advanced Templating and Class-Based Views....518

Technical requirements....519

Template filters....519

Custom template filters....520

Creating custom template filters....521

Implementing the custom filter function....522

Using custom filters inside templates....522

Exercise 11.01 – Creating a custom template filter....523

String filters....526

Template tags....527

The types of template tags....528

Simple tags....528

Creating a simple template tag....528

Exercise 11.02 – Creating a custom simple tag....530

Inclusion tags....533

Exercise 11.03 – Building a custom inclusion tag....535

Django views....538

Class-based views....538

Exercise 11.04 – Creating a book catalog using a CBV....540

CRUD operations with CBVs....546

The Read view....547

Activity 11.01 – Rendering details on the user profile page using inclusion tags....551

Summary....553

Chapter 12: Building a REST API....554

Technical requirements....555

Understanding REST APIs....555

Django REST framework....555

Installation and configuration....556

Functional API views....556

Understanding serializers....559

Class-based API views and generic views....562

Activity 12.01 – creating an API endpoint for a top contributors page....567

Simplifying the code using ViewSets....568

URL configuration using routers and Viewsets....569

Exercise 12.04 – using ViewSets and routers....569

Implementing authentication....573

Token-based authentication....574

Exercise 12.05 – omplementing token-based authentication for Bookr APIs....574

Summary....579

Chapter 13: Generating CSV, PDF, and Other Binary Files....580

Technical requirements....581

Working with CSV files inside Python....581

Working with Python’s csv module....581

Reading data from a CSV file....581

Exercise 13.0 – reading a CSV file with Python....582

Writing to CSV files using Python....585

Exercise 13.02 – generating a CSV file using Python’s csv module....586

A better way to read and write CSV files....589

Working with Excel files in Python....591

Binary file formats for data exports....592

Working with XLSX files using the XlsxWriter package....592

XLSX files....592

Exercise 13.03 – creating XLSX files in Python....595

Working with PDF files in Python....598

Converting web pages into PDFs....598

Exercise 13.04 – generating a PDF version of a web page in Python....598

Playing with graphs in Python....601

Integrating plotly with Django....606

Integrating visualizations with Django....606

Exercise 13.06 – visualizing a user’s reading history on the user’s profile page....606

Activity 13.01 – exporting the books read by a user as an XLSLX file....612

Summary....613

Chapter 14: Testing Your Django Applications....614

Technical requirements....615

Importance of testing....615

Automation testing....615

Testing in Django....616

Implementing test cases....617

Unit testing in Django....617

Utilizing assertions....617

Exercise 14.01 – writing a simple unit test....619

Performing pre-test setup and cleanup after every test case run....621

Testing Django models....622

Exercise 14.02 – testing Django models....622

Testing Django views....626

Exercise 14.03 – writing unit tests for Django views....627

Testing views with authentication....630

Exercise 14.04 – writing test cases to validate authenticated users....631

Django RequestFactory....635

Exercise 14.05 – using RequestFactory to test views....635

Testing class-based views....638

Test case classes in Django....638

The SimpleTestCase class....639

The TransactionTestCase class....639

The LiveServerTestCase class....639

Modularizing test code....640

Activity 14.01 – testing models and views in Bookr....641

Summary....642

Chapter 15: Django Third-Party Libraries....644

Technical requirements....645

Environment variables....645

django-configurations....648

manage.py changes....650

Configuration from environment variables....651

Exercise 15.01 – Django configurations setup....652

dj-database-url....656

Exercise 15.02 – dj-database-url and setup....660

The Django Debug Toolbar....661

Exercise 15.03 – setting up the Django Debug Toolbar....678

django-crispy-forms....681

The crispy filter....682

The crispy template Tag....683

Exercise 15.04 – using Django Crispy Forms with SearchForm....685

django-allauth....690

django-allauth installation and setup....693

Initiating authentication with django-allauth....696

Other django-allauth features....696

Activity 15.01 – using FormHelper to update forms....697

Summary....700

Chapter 16: Using a Frontend JavaScript Library with Django....702

Technical requirements....702

JavaScript frameworks....703

An introduction to JavaScript ....705

Loading JavaScript....705

Variables and constants....706

Working with React....711

Components....712

Exercise 16.01 – setting up a React example....717

JSX – a JavaScript syntax extension....720

Exercise 16.02 – JSX and Babel....722

JSX properties....723

Exercise 16.03 – React component properties....724

JavaScript promises....726

The fetch function....727

Exercise 16.04 – fetching and rendering books....731

The verbatim template tag....735

Activity 16.01 – reviews preview....736

Summary....742

Index....744

Other Books You May Enjoy....759

Do you want to develop reliable and secure applications that stand out from the crowd without spending hours on boilerplate code? You've made the right choice trusting the Django framework, and this book will tell you why. Often referred to as a "batteries included" web development framework, Django comes with all the core features needed to build a standalone application. Web Development with Django will take you through all the essential concepts and help you explore its power to build real-world applications using Python.

Throughout the book, you'll get the grips with the major features of Django by building a website called Bookr - a repository for book reviews. This end-to-end case study is split into a series of bitesize projects presented as exercises and activities, allowing you to challenge yourself in an enjoyable and attainable way. As you advance, you'll acquire various practical skills, including how to serve static files to add CSS, JavaScript, and images to your application, how to implement forms to accept user input, and how to manage sessions to ensure a reliable user experience. You'll cover everyday tasks that are part of the development cycle of a real-world web application.

By the end of this Django book, you'll have the skills and confidence to creatively develop and deploy your own projects.

What you will learn

• Create a new application and add models to describe your data
• Use views and templates to control behavior and appearance
• Implement access control through authentication and permissions
• Develop practical web forms to add features such as file uploads
• Build a RESTful API and JavaScript code that communicates with it
• Connect to a database such as PostgreSQL

Who this book is for

This book is for programmers looking to enhance their web development skills using the Django framework. To fully understand the concepts explained in this book, basic knowledge of Python programming as well as familiarity with JavaScript, HTML, and CSS is assumed.