Search icon CANCEL
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Conferences
Free Learning
Arrow right icon
Django 2 Web Development Cookbook
Django 2 Web Development Cookbook

Django 2 Web Development Cookbook: 100 practical recipes on building scalable Python web apps with Django 2 , Third Edition

Arrow left icon
Profile Icon Jake Kronika Profile Icon Aidas Bendoraitis
Arrow right icon
€36.99
Full star icon Full star icon Full star icon Full star icon Empty star icon 4 (6 Ratings)
Paperback Oct 2018 544 pages 3rd Edition
eBook
€20.98 €29.99
Paperback
€36.99
Subscription
Free Trial
Renews at €18.99p/m
Arrow left icon
Profile Icon Jake Kronika Profile Icon Aidas Bendoraitis
Arrow right icon
€36.99
Full star icon Full star icon Full star icon Full star icon Empty star icon 4 (6 Ratings)
Paperback Oct 2018 544 pages 3rd Edition
eBook
€20.98 €29.99
Paperback
€36.99
Subscription
Free Trial
Renews at €18.99p/m
eBook
€20.98 €29.99
Paperback
€36.99
Subscription
Free Trial
Renews at €18.99p/m

What do you get with Print?

Product feature icon Instant access to your digital eBook copy whilst your Print order is Shipped
Product feature icon Paperback book shipped to your preferred address
Product feature icon Download this book in EPUB and PDF formats
Product feature icon Access this title in our online reader with advanced features
Product feature icon DRM FREE - Read whenever, wherever and however you want
Table of content icon View table of contents Preview book icon Preview Book

Django 2 Web Development Cookbook

Database Structure and Modeling

In this chapter, we will cover the following topics:

  • Using model mixins
  • Creating a model mixin with URL-related methods
  • Creating a model mixin to handle creation and modification dates
  • Creating a model mixin to take care of meta tags
  • Creating a model mixin to handle generic relations
  • Handling multilingual fields
  • Enabling schema microdata enhancements
  • Using migrations
  • Switching from South migrations to Django migrations
  • Changing a foreign key to the many-to-many field

Introduction

When you start a new app, the first thing that you do is create the models that represent your database structure. We are assuming that you have already created Django apps, or, at the very least, have read and understood the official Django tutorial. In this chapter, you will see a few interesting techniques that will make your database structure consistent throughout the different apps in your project. Then, you will see how to create custom model fields, in order to handle the internationalization of the data in your database. At the end of the chapter, you will see how to use migrations to change your database structure during the process of development.

Using model mixins

In object-oriented languages, such as Python, a mixin class can be viewed as an interface with implemented features. When a model extends a mixin, it implements the interface and includes all of its fields, properties, and methods. The mixins in Django models can be used when you want to reuse the generic functionalities in different models multiple times.

Getting ready

First, you will need to create reusable mixins. A good place to keep your model mixins is in a utils module, such as the one that we will create later in the chapter (along with some typical examples of mixins). If you create a reusable app that you will share with others, keep the model mixins in the reusable app, instead—possibly...

Creating a model mixin with URL-related methods

For every model that is appropriate to detail on its own distinct page, it is a good practice to define the get_absolute_url() method. This method can be used in templates, and also in the Django admin site, to preview the saved object. However, get_absolute_url() is ambiguous, as it returns the URL path instead of the full URL.

In this recipe, we will look at how to create a model mixin that provides simplified support for model-specific URLs. This mixin will:

  • Allow you to define either the URL path or the full URL in your model
  • Generate the other of these automatically based on the one you define
  • Define the get_absolute_url() method behind the scenes

Getting ready

If you...

Creating a model mixin to handle creation and modification dates

It is common to include timestamps in your models, for the creation and modification of your model instances. In this recipe, you will learn how to create a simple model mixin that saves the creation and modification dates and times for your model. Using such a mixin will ensure that all of the models use the same field names for the timestamps, and have the same behaviors.

Getting ready

If you haven't yet done so, create the utils package to save your mixins. Then, create the models.py file in the utils package.

How to do it...

...

Creating a model mixin to take care of meta tags

When you optimize your site for search engines, you not only have to use semantic markup for each page, but you also have to include appropriate meta tags. For maximum flexibility, it helps to have a way to define content for common meta tags, specific to objects that have their own detail pages on your website. In this recipe, we will look at how to create a model mixin for the fields and methods related to keyword, description, author, and copyright meta tags.

Getting ready

As detailed in the previous recipes, make sure that you have the utils package for your mixins. Also, create a directory structure, templates/utils, under the package, and inside of that, create a meta...

Creating a model mixin to handle generic relations

Aside from normal database relationships, such as a foreign-key relationship or a many-to-many relationship, Django has a mechanism to relate a model to an instance of any other model. This concept is called generic relations. For each generic relation, there is a content type of the related model that is saved, as well as the ID of the instance of that model.

In this recipe, we will look at how to abstract the creation of generic relations in the model mixins.

Getting ready

For this recipe to work, you will need to have the contenttypes app installed. It should be in the INSTALLED_APPS directory, by default, as shown in the following code:

# settings.py or config/base.py
INSTALLED_APPS...

Handling multilingual fields

Django uses the internationalization mechanism to translate verbose strings in the code and templates. However, it's up to the developer to decide how to implement the multilingual content in the models. There are several third-party modules that handle translatable model fields; however, I prefer the simple solution that will be introduced to you in this recipe.

The advantages of the approach that you will learn about are as follows:

  • It is straightforward to define multilingual fields in the database.
  • It is simple to use the multilingual fields in database queries.
  • You can use contributed administration to edit models with the multilingual fields, without additional modifications.
  • If you need it, you can easily show all of the translations of an object in the same template.
  • You can use database migrations to add or remove languages.
...

Enabling schema microdata enhancements

The content delivered in a web application is generally very rich, but there are often important details embedded within plain human-readable text, and search engines cannot easily understand them. When such additional information becomes available, though, search result entries for the content can be similarly enriched, increasing SEO rankings and making it easier for users to find what they are looking for.

Part of this is the data that we exposed in the Creating a model mixin to take care of meta tags recipe, earlier in the chapter; however, for certain types of objects, you can build something even more structured. To make this possible, you can identify schema microdata, as per the https://schema.org specification, for objects that are represented in the application. In this recipe, we will approach the creation of a model mixin for...

Using migrations

It is not true that once you have created your database structure, it won't change in the future. As development happens iteratively, you can get updates on the business requirements in the development process, and you will have to perform database schema changes along the way. With Django migrations, you don't have to change the database tables and fields manually, as most of it is done automatically, using the command-line interface.

Getting ready

Activate your virtual environment or Docker project in the command-line tool.

How to do it...

...

Switching from South migrations to Django migrations

If you were using Django before version 1.7 introduced database migrations into the core functionality, you have more than likely used third-party South migrations before. In this recipe, you will learn how to switch your project from South migrations to Django migrations.

Getting ready

Make sure that all apps, along with their South migrations, are up to date.

How to do it...

Execute the following steps:

  1. Migrate all of your apps to the latest South migrations, as follows:
(myproject_env)$ python3 manage.py migrate...

Changing a foreign key to the many-to-many field

This recipe is a practical example of how to change a many-to-one relation to a many-to-many relation, while preserving the already existing data. We will use both schema and data migrations in this situation.

Getting ready

Let's suppose that you have the Idea model, with a foreign key pointing to the Category model, as follows:

# demo_app/models.py 
from django.db import models 
from django.utils.translation import ugettext_lazy as _ 
 
class Category(models.Model):
    title = models.CharField(_("Title"), max_length=200)

    def __str__(self):
        return self.title
 
class Idea(models.Model):
    title = model.CharField(
_("Title"),
...
Left arrow icon Right arrow icon

Key benefits

  • Discover solutions to a variety of web application scenarios, leveraging the power of the Django framework
  • Understand URL routing, models, forms, templates, and RESTful services with Django 2.14
  • Test, deploy, and scale your web applications efficiently with Amazon Web Services

Description

Django is a framework designed to balance rapid web development with high performance. It handles high levels of user traffic and interaction, integrates with a variety of databases, and collects and processes data in real time. This book follows a task-based approach to guide you through developing with the Django 2.1 framework, starting with setting up and configuring Docker containers and a virtual environment for your project. You'll learn how to write reusable pieces of code for your models and manage database changes. You'll work with forms and views to enter and list data, applying practical examples using templates and JavaScript together for the optimum user experience. This cookbook helps you to adjust the built-in Django administration to fit your needs and sharpen security and performance to make your web applications as robust, scalable, and dependable as possible. You'll also explore integration with Django CMS, the popular content management suite. In the final chapters, you'll learn programming and debugging tricks and discover how collecting data from different sources and providing it to others in various formats can be a breeze. By the end of the book, you'll learn how to test and deploy projects to a remote dedicated server and scale your application to meet user demands.

Who is this book for?

This book is designed for Python developers working on fast and secure web apps that can scale over time. You’ll also find this book useful if you want to upgrade to latest Django framework. A background in Python 3 along with basic knowledge of the Django framework will be useful.

What you will learn

  • Get started with the basic configuration necessary to start any Django project
  • Build a database structure out of reusable model mixins
  • Secure web applications against malicious usage and address common performance bottlenecks
  • Integrate with, and extend, the Django CMS
  • Construct and manage complex and deep hierarchies
  • Import data from local sources and external web services and export it to third parties
Estimated delivery fee Deliver to Estonia

Premium delivery 7 - 10 business days

€25.95
(Includes tracking information)

Product Details

Country selected
Publication date, Length, Edition, Language, ISBN-13
Publication date : Oct 31, 2018
Length: 544 pages
Edition : 3rd
Language : English
ISBN-13 : 9781788837682
Vendor :
Django
Languages :
Tools :

What do you get with Print?

Product feature icon Instant access to your digital eBook copy whilst your Print order is Shipped
Product feature icon Paperback book shipped to your preferred address
Product feature icon Download this book in EPUB and PDF formats
Product feature icon Access this title in our online reader with advanced features
Product feature icon DRM FREE - Read whenever, wherever and however you want
Estimated delivery fee Deliver to Estonia

Premium delivery 7 - 10 business days

€25.95
(Includes tracking information)

Product Details

Publication date : Oct 31, 2018
Length: 544 pages
Edition : 3rd
Language : English
ISBN-13 : 9781788837682
Vendor :
Django
Languages :
Tools :

Packt Subscriptions

See our plans and pricing
Modal Close icon
€18.99 billed monthly
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Simple pricing, no contract
€189.99 billed annually
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Choose a DRM-free eBook or Video every month to keep
Feature tick icon PLUS own as many other DRM-free eBooks or Videos as you like for just €5 each
Feature tick icon Exclusive print discounts
€264.99 billed in 18 months
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Choose a DRM-free eBook or Video every month to keep
Feature tick icon PLUS own as many other DRM-free eBooks or Videos as you like for just €5 each
Feature tick icon Exclusive print discounts

Frequently bought together


Stars icon
Total 115.97
Django Design Patterns and Best Practices
€36.99
Django 2 Web Development Cookbook
€36.99
Django 2 by Example
€41.99
Total 115.97 Stars icon

Table of Contents

13 Chapters
Getting Started with Django 2.1 Chevron down icon Chevron up icon
Database Structure and Modeling Chevron down icon Chevron up icon
Forms and Views Chevron down icon Chevron up icon
Templates and JavaScript Chevron down icon Chevron up icon
Customizing Template Filters and Tags Chevron down icon Chevron up icon
Model Administration Chevron down icon Chevron up icon
Security and Performance Chevron down icon Chevron up icon
Django CMS Chevron down icon Chevron up icon
Hierarchical Structures Chevron down icon Chevron up icon
Importing and Exporting Data Chevron down icon Chevron up icon
Bells and Whistles Chevron down icon Chevron up icon
Testing and Deployment Chevron down icon Chevron up icon
Other Books You May Enjoy Chevron down icon Chevron up icon

Customer reviews

Top Reviews
Rating distribution
Full star icon Full star icon Full star icon Full star icon Empty star icon 4
(6 Ratings)
5 star 66.7%
4 star 0%
3 star 16.7%
2 star 0%
1 star 16.7%
Filter icon Filter
Top Reviews

Filter reviews by




R. Truman Jan 11, 2019
Full star icon Full star icon Full star icon Full star icon Full star icon 5
Django 2 Web Development Cookbook is well organized and very detailed. This is a reference guide you'll want on hand or a great place to start if you are new to developing with Django. Jake even takes the time to explore and detail setting up your environment and covers a variety of approaches for doing so. If you are looking for a book that will help expand your knowledge and improve your Django 2 development, start here.
Amazon Verified review Amazon
MMenon Nov 28, 2018
Full star icon Full star icon Full star icon Full star icon Full star icon 5
I liked this book. People who are interested in Phython, Docker & Django will most probably be interested in reading this book. Readers can gain knowledge. This book was very well written with ample examples and sample codes.
Amazon Verified review Amazon
Charudatta Katdare Dec 20, 2018
Full star icon Full star icon Full star icon Full star icon Full star icon 5
Using the book for a month now and have to save most of the scenarios required for development in Django are covered. The examples provided are very useful and explanation concise. The book should benefit both beginners and advanced developers in Django.
Amazon Verified review Amazon
C.J.S. Hayward Jan 16, 2019
Full star icon Full star icon Full star icon Full star icon Full star icon 5
I'm biased in regards to reviewing this book. I've worked with Jake Kronika in the past and I would work with him again in a heartbeat.That stated, the book so far as I have read it is an authoritative, comprehensive, decisive guide that is better than anything technical I've written (but see my author bookshelf for mostly non-IT works, some of which have good reviews ).I have looked through the title briefly, and I regard my free review copy as an informational windfall. I've looked at it a bit, and I expect I'll be diving in full force next Django project!
Amazon Verified review Amazon
Cavatica Sep 19, 2019
Full star icon Full star icon Full star icon Empty star icon Empty star icon 3
Not what I was looking for or expected. Amazon says "a basic understanding of the Django framework will be beneficial", but the book says go read the standard Django tutorial. And the first chapter is about virtualenv and docker and gets bogged down at the Unix command line, in all kinds of configuration minutiae.
Amazon Verified review Amazon
Get free access to Packt library with over 7500+ books and video courses for 7 days!
Start Free Trial

FAQs

What is the delivery time and cost of print book? Chevron down icon Chevron up icon

Shipping Details

USA:

'

Economy: Delivery to most addresses in the US within 10-15 business days

Premium: Trackable Delivery to most addresses in the US within 3-8 business days

UK:

Economy: Delivery to most addresses in the U.K. within 7-9 business days.
Shipments are not trackable

Premium: Trackable delivery to most addresses in the U.K. within 3-4 business days!
Add one extra business day for deliveries to Northern Ireland and Scottish Highlands and islands

EU:

Premium: Trackable delivery to most EU destinations within 4-9 business days.

Australia:

Economy: Can deliver to P. O. Boxes and private residences.
Trackable service with delivery to addresses in Australia only.
Delivery time ranges from 7-9 business days for VIC and 8-10 business days for Interstate metro
Delivery time is up to 15 business days for remote areas of WA, NT & QLD.

Premium: Delivery to addresses in Australia only
Trackable delivery to most P. O. Boxes and private residences in Australia within 4-5 days based on the distance to a destination following dispatch.

India:

Premium: Delivery to most Indian addresses within 5-6 business days

Rest of the World:

Premium: Countries in the American continent: Trackable delivery to most countries within 4-7 business days

Asia:

Premium: Delivery to most Asian addresses within 5-9 business days

Disclaimer:
All orders received before 5 PM U.K time would start printing from the next business day. So the estimated delivery times start from the next day as well. Orders received after 5 PM U.K time (in our internal systems) on a business day or anytime on the weekend will begin printing the second to next business day. For example, an order placed at 11 AM today will begin printing tomorrow, whereas an order placed at 9 PM tonight will begin printing the day after tomorrow.


Unfortunately, due to several restrictions, we are unable to ship to the following countries:

  1. Afghanistan
  2. American Samoa
  3. Belarus
  4. Brunei Darussalam
  5. Central African Republic
  6. The Democratic Republic of Congo
  7. Eritrea
  8. Guinea-bissau
  9. Iran
  10. Lebanon
  11. Libiya Arab Jamahriya
  12. Somalia
  13. Sudan
  14. Russian Federation
  15. Syrian Arab Republic
  16. Ukraine
  17. Venezuela
What is custom duty/charge? Chevron down icon Chevron up icon

Customs duty are charges levied on goods when they cross international borders. It is a tax that is imposed on imported goods. These duties are charged by special authorities and bodies created by local governments and are meant to protect local industries, economies, and businesses.

Do I have to pay customs charges for the print book order? Chevron down icon Chevron up icon

The orders shipped to the countries that are listed under EU27 will not bear custom charges. They are paid by Packt as part of the order.

List of EU27 countries: www.gov.uk/eu-eea:

A custom duty or localized taxes may be applicable on the shipment and would be charged by the recipient country outside of the EU27 which should be paid by the customer and these duties are not included in the shipping charges been charged on the order.

How do I know my custom duty charges? Chevron down icon Chevron up icon

The amount of duty payable varies greatly depending on the imported goods, the country of origin and several other factors like the total invoice amount or dimensions like weight, and other such criteria applicable in your country.

For example:

  • If you live in Mexico, and the declared value of your ordered items is over $ 50, for you to receive a package, you will have to pay additional import tax of 19% which will be $ 9.50 to the courier service.
  • Whereas if you live in Turkey, and the declared value of your ordered items is over € 22, for you to receive a package, you will have to pay additional import tax of 18% which will be € 3.96 to the courier service.
How can I cancel my order? Chevron down icon Chevron up icon

Cancellation Policy for Published Printed Books:

You can cancel any order within 1 hour of placing the order. Simply contact customercare@packt.com with your order details or payment transaction id. If your order has already started the shipment process, we will do our best to stop it. However, if it is already on the way to you then when you receive it, you can contact us at customercare@packt.com using the returns and refund process.

Please understand that Packt Publishing cannot provide refunds or cancel any order except for the cases described in our Return Policy (i.e. Packt Publishing agrees to replace your printed book because it arrives damaged or material defect in book), Packt Publishing will not accept returns.

What is your returns and refunds policy? Chevron down icon Chevron up icon

Return Policy:

We want you to be happy with your purchase from Packtpub.com. We will not hassle you with returning print books to us. If the print book you receive from us is incorrect, damaged, doesn't work or is unacceptably late, please contact Customer Relations Team on customercare@packt.com with the order number and issue details as explained below:

  1. If you ordered (eBook, Video or Print Book) incorrectly or accidentally, please contact Customer Relations Team on customercare@packt.com within one hour of placing the order and we will replace/refund you the item cost.
  2. Sadly, if your eBook or Video file is faulty or a fault occurs during the eBook or Video being made available to you, i.e. during download then you should contact Customer Relations Team within 14 days of purchase on customercare@packt.com who will be able to resolve this issue for you.
  3. You will have a choice of replacement or refund of the problem items.(damaged, defective or incorrect)
  4. Once Customer Care Team confirms that you will be refunded, you should receive the refund within 10 to 12 working days.
  5. If you are only requesting a refund of one book from a multiple order, then we will refund you the appropriate single item.
  6. Where the items were shipped under a free shipping offer, there will be no shipping costs to refund.

On the off chance your printed book arrives damaged, with book material defect, contact our Customer Relation Team on customercare@packt.com within 14 days of receipt of the book with appropriate evidence of damage and we will work with you to secure a replacement copy, if necessary. Please note that each printed book you order from us is individually made by Packt's professional book-printing partner which is on a print-on-demand basis.

What tax is charged? Chevron down icon Chevron up icon

Currently, no tax is charged on the purchase of any print book (subject to change based on the laws and regulations). A localized VAT fee is charged only to our European and UK customers on eBooks, Video and subscriptions that they buy. GST is charged to Indian customers for eBooks and video purchases.

What payment methods can I use? Chevron down icon Chevron up icon

You can pay with the following card types:

  1. Visa Debit
  2. Visa Credit
  3. MasterCard
  4. PayPal
What is the delivery time and cost of print books? Chevron down icon Chevron up icon

Shipping Details

USA:

'

Economy: Delivery to most addresses in the US within 10-15 business days

Premium: Trackable Delivery to most addresses in the US within 3-8 business days

UK:

Economy: Delivery to most addresses in the U.K. within 7-9 business days.
Shipments are not trackable

Premium: Trackable delivery to most addresses in the U.K. within 3-4 business days!
Add one extra business day for deliveries to Northern Ireland and Scottish Highlands and islands

EU:

Premium: Trackable delivery to most EU destinations within 4-9 business days.

Australia:

Economy: Can deliver to P. O. Boxes and private residences.
Trackable service with delivery to addresses in Australia only.
Delivery time ranges from 7-9 business days for VIC and 8-10 business days for Interstate metro
Delivery time is up to 15 business days for remote areas of WA, NT & QLD.

Premium: Delivery to addresses in Australia only
Trackable delivery to most P. O. Boxes and private residences in Australia within 4-5 days based on the distance to a destination following dispatch.

India:

Premium: Delivery to most Indian addresses within 5-6 business days

Rest of the World:

Premium: Countries in the American continent: Trackable delivery to most countries within 4-7 business days

Asia:

Premium: Delivery to most Asian addresses within 5-9 business days

Disclaimer:
All orders received before 5 PM U.K time would start printing from the next business day. So the estimated delivery times start from the next day as well. Orders received after 5 PM U.K time (in our internal systems) on a business day or anytime on the weekend will begin printing the second to next business day. For example, an order placed at 11 AM today will begin printing tomorrow, whereas an order placed at 9 PM tonight will begin printing the day after tomorrow.


Unfortunately, due to several restrictions, we are unable to ship to the following countries:

  1. Afghanistan
  2. American Samoa
  3. Belarus
  4. Brunei Darussalam
  5. Central African Republic
  6. The Democratic Republic of Congo
  7. Eritrea
  8. Guinea-bissau
  9. Iran
  10. Lebanon
  11. Libiya Arab Jamahriya
  12. Somalia
  13. Sudan
  14. Russian Federation
  15. Syrian Arab Republic
  16. Ukraine
  17. Venezuela