Book Image

Web Development with Django Cookbook- Second Edition - Second Edition

By : Aidas Bendoraitis
Book Image

Web Development with Django Cookbook- Second Edition - Second Edition

By: Aidas Bendoraitis

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.
Table of Contents (18 chapters)
Web Development with Django Cookbook Second Edition
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Working with a virtual environment


It is very likely that you will develop multiple Django projects on your computer. Some modules such as Python Imaging Library (or Pillow) and MySQLdb, can be installed once and then shared for all projects. Other modules such as Django, third-party Python libraries, and Django apps, will need to be kept isolated from each other. The virtualenv tool is a utility that separates all the Python projects in their own realms. In this recipe, we will see how to use it.

Getting ready

To manage Python packages, you will need pip. It is included in your Python installation if you are using Python 2.7.9 or Python 3.4+. If you are using another version of Python, install pip by executing the installation instructions at http://pip.readthedocs.org/en/stable/installing/. Let's install the shared Python modules Pillow and MySQLdb, and the virtualenv utility, using the following commands:

$ sudo pip install Pillow
$ sudo pip install MySQL-python
$ sudo pip install virtualenv

How to do it…

Once you have your prerequisites installed, create a directory where all your Django projects will be stored, for example, virtualenvs under your home directory. Perform the following steps after creating the directory:

  1. Go to the newly created directory and create a virtual environment that uses the shared system site packages:

    $ cd ~/virtualenvs
    $ mkdir myproject_env
    $ cd myproject_env
    $ virtualenv --system-site-packages .
    New python executable in ./bin/python
    Installing setuptools………….done.
    Installing pip……………done.
    
  2. To use your newly created virtual environment, you need to execute the activation script in your current shell. This can be done with the following command:

    $ source bin/activate
    

    You can also use the following command one for the same (note the space between the dot and bin):

    $ . bin/activate
    
  3. You will see that the prompt of the command-line tool gets a prefix of the project name, as follows:

    (myproject_env)$
    
  4. To get out of the virtual environment, type the following command:

    $ deactivate
    

How it works…

When you create a virtual environment, a few specific directories (bin, build, include, and lib) are created in order to store a copy of the Python installation and some shared Python paths are defined. When the virtual environment is activated, whatever you have installed with pip or easy_install will be put in and used by the site packages of the virtual environment, and not the global site packages of your Python installation.

To install Django 1.8 in your virtual environment, type the following command:

(myproject_env)$ pip install Django==1.8

See also

  • The Creating a project file structure recipe

  • The Deploying on Apache with mod_wsgi recipe in Chapter 11, Testing and Deployment