Web Development with Django Cookbook- Second Edition

Web Development with Django Cookbook- Second Edition - Second Edition

By : Aidas Bendoraitis

Buy this Book

Web Development with Django Cookbook- Second Edition - Second Edition

By: Aidas Bendoraitis

Buy this Book

Overview of this book

Django is a web framework that was designed to strike a balance between rapid web development and high performance. It has the capacity to handle applications with high levels of user traffic and interaction, and can integrate with massive databases on the backend, constantly collecting and processing data in real time. Through this book, you'll discover that collecting data from different sources and providing it to others in different formats isn't as difficult as you thought. It follows a task-based approach to guide you through all the web development processes using the Django framework. We’ll start by setting up the virtual environment for a Django project and configuring it. Then you’ll learn to write reusable pieces of code for your models and find out how to manage database schema changes using South migrations. After that, we’ll take you through working with forms and views to enter and list data. With practical examples on using templates and JavaScript together, you will discover how to create the best user experience. In the final chapters, you'll be introduced to some programming and debugging tricks and finally, you will be shown how to test and deploy the project to a remote dedicated server. By the end of this book, you will have a good understanding of the new features added to Django 1.8 and be an expert at web development processes.

Web Development with Django Cookbook Second Edition

Credits

About the Author

About the Reviewers

www.PacktPub.com

Preface

Free Chapter

Getting Started with Django 1.8

Introduction

Working with a virtual environment

Creating a project file structure

Handling project dependencies with pip

Making your code compatible with both Python 2.7 and Python 3

Including external dependencies in your project

Configuring settings for development, testing, staging, and production environments

Defining relative paths in the settings

Creating and including local settings

Setting up STATIC_URL dynamically for Subversion users

Setting up STATIC_URL dynamically for Git users

Setting UTF-8 as the default encoding for MySQL configuration

Setting the Subversion ignore property

Creating the Git ignore file

Deleting Python-compiled files

Respecting the import order in Python files

Creating app configuration

Defining overwritable app settings

Database Structure

Introduction

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

Using migrations

Switching from South migrations to Django migrations

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

Forms and Views

Introduction

Passing HttpRequest to the form

Utilizing the save method of the form

Uploading images

Creating a form layout with django-crispy-forms

Downloading authorized files

Filtering object lists

Managing paginated lists

Composing class-based views

Generating PDF documents

Implementing a multilingual search with Haystack

Templates and JavaScript

Introduction

Arranging the base.html template

Including JavaScript settings

Using HTML5 data attributes

Opening object details in a modal dialog

Implementing a continuous scroll

Implementing the Like widget

Uploading images by Ajax

Custom Template Filters and Tags

Introduction

Following conventions for your own template filters and tags

Creating a template filter to show how many days have passed since a post was published

Creating a template filter to extract the first media object

Creating a template filter to humanize URLs

Creating a template tag to include a template if it exists

Creating a template tag to load a QuerySet in a template

Creating a template tag to parse content as a template

Creating a template tag to modify request query parameters

Model Administration

Introduction

Customizing columns on the change list page

Creating admin actions

Developing change list filters

Customizing default admin settings

Inserting a map into a change form

Django CMS

Introduction

Creating templates for Django CMS

Structuring the page menu

Converting an app to a CMS app

Attaching your own navigation

Writing your own CMS plugin

Adding new fields to the CMS page

Hierarchical Structures

Introduction

Creating hierarchical categories

Creating a category administration interface with django-mptt-admin

Creating a category administration interface with django-mptt-tree-editor

Rendering categories in a template

Using a single selection field to choose a category in forms

Using a checkbox list to choose multiple categories in forms

Data Import and Export

Introduction

Importing data from a local CSV file

Importing data from a local Excel file

Importing data from an external JSON file

Importing data from an external XML file

Creating filterable RSS feeds

Using Tastypie to create API

Using Django REST framework to create API

Bells and Whistles

Introduction

Using the Django shell

Using database query expressions

Monkey-patching the slugify() function for better internationalization support

Toggling the Debug Toolbar

Using ThreadLocalMiddleware

Caching the method return value

Using Memcached to cache Django views

Using signals to notify administrators about new entries

Checking for missing settings

Testing and Deployment

Introduction

Testing pages with Selenium

Testing views with mock

Testing API created using Django REST framework

Releasing a reusable Django app

Getting detailed error reporting via e-mail

Deploying on Apache with mod_wsgi

Setting up cron jobs for regular tasks

Creating and using the Fabric deployment script

Index

Customer Reviews

5 star

4 star

3 star

2 star

1 star

Making your code compatible with both Python 2.7 and Python 3

Since version 1.7, Django can be used with Python 2.7 and Python 3. In this recipe, we will take a look at the operations to make your code compatible with both the Python versions.

Getting ready

When creating a new Django project or upgrading an old existing project, consider following the rules given in this recipe.

How to do it…

Making your code compatible with both Python versions consists of the following steps:

At the top of each module, add from __future__ import unicode_literals and then use usual quotes without a u prefix for Unicode strings and a b prefix for bytestrings.
To ensure that a value is bytestring, use the django.utils.encoding.smart_bytes function. To ensure that a value is Unicode, use the django.utils.encoding.smart_text or django.utils.encoding.force_text function.

For your models, instead of the __unicode__ method, use the __str__ method and add the python_2_unicode_compatible decorator, as follows:

# models.py
# -*- coding: UTF-8 -*-
from __future__ import unicode_literals
from django.db import models
from django.utils.translation import ugettext_lazy as _
from django.utils.encoding import \
    python_2_unicode_compatible

@python_2_unicode_compatible
class NewsArticle(models.Model):
    title = models.CharField(_("Title"), max_length=200)
    content = models.TextField(_("Content"))

    def __str__(self):
        return self.title

    class Meta:
        verbose_name = _("News Article")
        verbose_name_plural = _("News Articles")

To iterate through dictionaries, use iteritems(), iterkeys(), and itervalues() from django.utils.six. Take a look at the following:

from django.utils.six import iteritems
d = {"imported": 25, "skipped": 12, "deleted": 3}
for k, v in iteritems(d):
    print("{0}: {1}".format(k, v))

When you capture exceptions, use the as keyword, as follows:

try:
    article = NewsArticle.objects.get(slug="hello-world")
except NewsArticle.DoesNotExist as exc:
    pass
except NewsArticle.MultipleObjectsReturned as exc:
    pass

To check the type of a value, use django.utils.six, as shown in the following:

from django.utils import six
isinstance(val, six.string_types) # previously basestring
isinstance(val, six.text_type) # previously unicode
isinstance(val, bytes) # previously str
isinstance(val, six.integer_types) # previously (int, long)

Instead of xrange, use range from django.utils.six.moves, as follows:

from django.utils.six.moves import range
for i in range(1, 11):
    print(i)

To check whether the current version is Python 2 or Python 3, you can use the following conditions:

from django.utils import six
if six.PY2:
    print("This is Python 2")
if six.PY3:
    print("This is Python 3")

How it works…

All strings in Django projects should be considered as Unicode strings. Only the input of HttpRequest and output of HttpResponse is usually in the UTF-8 encoded bytestring.

Many functions and methods in Python 3 now return the iterators instead of lists, which make the language more efficient. To make the code compatible with both the Python versions, you can use the six library that is bundled in Django.

Read more about writing compatible code in the official Django documentation at https://docs.djangoproject.com/en/1.8/topics/python3/.

Tip

Downloading the example code

You can download the example code files for all Packt books that you have purchased from your account at http://www.packtpub.com. If you purchased this book elsewhere, you can visit http://www.packtpub.com/support and register in order to have the files e-mailed directly to you.

Web Development with Django Cookbook- Second Edition - Second Edition

By : Aidas Bendoraitis

Web Development with Django Cookbook- Second Edition - Second Edition

By: Aidas Bendoraitis

Overview of this book

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Current Title:

Web Development with Django Cookbook- Second Edition - Second Edition

Making your code compatible with both Python 2.7 and Python 3

Getting ready

How to do it…

How it works…

Tip