Chapter 2: Getting Started¶
Installing Django is a multi-step process, due to the multiple moving parts in modern Web development environments. In this chapter, we’ll walk you through how to install the framework and its few dependencies.
Because Django is “just” Python code, it runs anywhere Python does – including on some cell phones! But this chapter just covers the common scenarios for Django installations. We’ll assume you’re installing it either on a desktop/laptop machine or a server.
Later, in Chapter 12, we’ll cover how to deploy Django to a production site.
Django itself is written purely in Python, so the first step in installing the framework is to make sure you have Python installed.
The core Django framework works with any Python version from 2.5 to 2.7, inclusive.
If you’re not sure which version of Python to install and you have complete freedom over the decision, pick the latest one in the 2.x series: version 2.7. Plus, certain third-party Django add-ons that you might want to use might require a version newer than Python 2.5, so using a later version of Python keeps your options open.
Django and Python 3.X:
Django 1.4 will drop support for Python 2.4, establishing a minimum requirement of 2.5.
Django 1.5 will then drop Python 2.5 support, setting the minimum at 2.6. Additionally, Django 1.5 will begin the process of porting the codebase, and will experimentally support Python 3, through the 2/3 compatibility features in Python 2.6 and 2.7. From https://www.djangoproject.com/weblog/2012/mar/13/py3k/
If you’re new to Python and are wondering whether to learn Python 2.x or Python 3.x, our advice is to start with 2.x and progress after 1.5 release with 3.x.
If you’re on Linux or Mac OS X, you probably have Python already installed.
python at a command prompt (or in Applications/Utilities/Terminal, in
OS X). If you see something like this, then Python is installed:
$ python Python 2.7.3 (default, Apr 20 2012, 22:39:59) [GCC 4.6.3] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>>
Otherwise, you’ll need to download and install Python. It’s fast and easy, and detailed instructions are available at http://www.python.org/download/
At any given time, two distinct versions of Django are available to you: the latest official release and the bleeding-edge “trunk” version. The version you decide to install depends on your priorities. Do you want a stable and tested version of Django, or do you want a version containing the latest features, perhaps so you can contribute to Django itself, at the expense of stability?
We’d recommend sticking with an official release, but it’s important to know that the “trunk” development version exists, because you’ll find it mentioned in the documentation and by members of the community.
Installing an Official Release¶
Official releases have a version number, such 1.4, and the latest one is always available at http://www.djangoproject.com/download/.
If you’re on a Linux distribution that includes a package of Django, it’s a good idea to use the distributor’s version. That way, you’ll get security updates along with the rest of your system packages.
If you don’t have access to a prepackaged version, you can download and install
the framework manually. To do so, first download the tarball, which will be
named something like
Django-1.4.x.tar.gz. (It doesn’t matter which
local directory you download this file into; the installation process will put
Django’s files in the right place.) Then, unzip it and run
as you do with most Python libraries.
Here’s how the automate process looks on Unix systems using pip:
$ pip install django
Here’s how tar.gz install process looks on Unix systems:
$ tar xzvf Django-1.4.x.tar.gz $ cd Django-* $ sudo python setup.py install
On Windows, we recommend using 7-Zip (http://www.djangoproject.com/r/7zip/)
.tar.gz files. Once you’ve unzipped the file, start up a DOS
shell (the “Command Prompt”) with administrator privileges and run the
following command from within the directory whose name starts with
python setup.py install
In case you’re curious: Django’s files will be installed into your Python
dist-packages directory – a directory where Python looks
for third-party libraries. Usually it’s in a place like (In Ubuntu 12.04)
Installing the “master” Version¶
The latest and greatest Django development version is referred to as master, and it’s available from Django’s git repository. You should consider installing this version if you want to work on the bleeding edge, or if you want to contribute code to Django itself.
Git is a free, open source distributed revision-control system, and the Django team uses it to manage changes to the Django codebase. You can use a Git client to grab the very latest Django source code and, at any given time, you can update your local version of the Django code, known as your local checkout, to get the latest changes and improvements made by Django developers.
When using master, keep in mind there’s no guarantee things won’t be broken at any given moment. With that said, though, some members of the Django team run production sites on master, so they have an incentive to keep it stable.
To grab the latest Django master, follow these steps:
Check out the master using the command
git clone https://github.com/django/django.git djmaster.
Locate your Python installation’s
dist-packagesdirectory. Usually it’s in a place like
./usr/local/lib/python2.7/dist-packages/. If you have no idea, type this command from a command prompt:python -c 'import sys, pprint; pprint.pprint(sys.path)'
The resulting output should include your
- # Within the
site-packagesdirectory, create a file called
django.pthand edit it to contain the full path to your
djmasterdirectory to it. For example, the file could just contain this line:/home/me/code/djmaster
djmaster/django/binon your system PATH. This directory includes management utilities such as
.pth files are new to you, you can learn more about them at
After downloading from Git and following the preceding steps, there’s no
need to run
python setup.py install– you’ve just done the work by hand!
Because the Django master changes often with bug fixes and feature additions,
you’ll probably want to update it every once in a while. To update the code,
just run the command
git pull from within the
djmaster directory. When
you run that command, Git will contact https://github.com/django/,
determine whether any of Django’s code has changed, and update your local
version of the code with any changes that have been made since you last
updated. It’s quite slick.
Finally, if you use master, you should know how to figure out which version of
master you’re running. Knowing your version number is important if you ever need
to reach out to the community for help, or if you submit improvements to the
framework. In these cases, you should tell people the master version, also known
as a “revision number” or “changeset,” that you’re using. To find out your
revision number, type “svn info” from within the
djtrunk directory, and
look for the number after “Revision:”. This number is incremented each time
Django is changed, whether through a bug fix, feature addition, documentation
improvement or anything else. Among some members of the Django community, it’s
a badge of honor to be able to say, “I’ve been using Django since [insert very
low revision number here].”
Installing Django in virtualenv with pip¶
To install django in a virtual environment with pip:
$ mkdir test $ cd test $ virtualenv venv New python executable in venv/bin/python Installing distribute..............done. Installing pip...............done. $ source venv/bin/activate $ pip install django Downloading/unpacking django Downloading Django-1.4.1.tar.gz (7.7Mb): 7.7Mb downloaded Running setup.py egg_info for package django Installing collected packages: django Running setup.py install for django changing mode of build/scripts-2.7/django-admin.py from 644 to 755 changing mode of /home/user/test/venv/bin/django-admin.py to 755 Successfully installed django Cleaning up...
To install a specific version of Django in a virtual environment with pip, use:
$ pip install django==1.4.1
Notice the == necessary to specify a specific version.
Testing the Django installation¶
For some post-installation positive feedback, take a moment to test whether the
installation worked. In a command shell, change into another directory (e.g.,
not the directory that contains the
django directory) and start the
Python interactive interpreter by typing
python. If the installation was
successful, you should be able to import the module
>>> import django >>> django.VERSION (1, 4, 1, 'final', 1)
Interactive Interpreter Examples
The Python interactive interpreter is a command-line program that lets you
write a Python program interactively. To start it, run the command
python at the command line.
Throughout this book, we feature example Python interactive interpreter
sessions. You can recognize these examples by the triple
greater-than signs (
>>>), which designate the interpreter’s prompt. If
you’re copying examples from this book, don’t copy those greater-than signs.
Multiline statements in the interactive interpreter are padded with three
...). For example:
>>> print """This is a ... string that spans ... three lines.""" This is a string that spans three lines. >>> def my_function(value): ... print value >>> my_function('hello') hello
Those three dots at the start of the additional lines are inserted by the Python shell – they’re not part of our input. We include them here to be faithful to the actual output of the interpreter. If you copy our examples to follow along, don’t copy those dots.
Setting Up a Database¶
At this point, you could very well begin writing a Web application with Django, because Django’s only hard-and-fast prerequisite is a working Python installation. However, odds are you’ll be developing a database-driven Web site, in which case you’ll need to configure a database server.
If you just want to start playing with Django, skip ahead to the “Starting a Project” section – but keep in mind that all the examples in this book assume you have a working database set up.
Django supports many database engines:
For the most part, all the engines here work equally well with the core Django framework. . If you’re not tied to any legacy system and have the freedom to choose a database backend, we recommend FirebirdSQL, which achieves a fine balance between cost, features, speed and stability.
Setting up the database is a two-step process:
- First, you’ll need to install and configure the database server itself. This process is beyond the scope of this book, but each of the four database backends has rich documentation on its Web site. (If you’re on a shared hosting provider, odds are that they’ve set this up for you already.)
- Second, you’ll need to install the Python library for your particular database backend. This is a third-party bit of code that allows Python to interface with the database. We outline the specific, per-database requirements in the following sections.
Using Django with FirebirdSQL¶
If you’re using FirebirdSQL, you’ll need to install either the
fdb package from http://pypi.python.org/pypi/fdb. We recommend
as it’s newer, more actively developed and can be easier to install.
pip install fdb
If you’re on Linux, check whether your distribution’s package-management
system offers a package called
Using Django with Postgresql¶
If you’re using Postgresql, you’ll need the psycopg package. Django 1.3 supports both version 1 and 2. When you configure Django’s database layer, specify either postgresql (for version 1) or postgresql_psycopg2 (for version 2). Django >=1.4 supports version 2. psycopg2 can be installed using pip:
pip install psycopg2
Using Django Without a Database¶
As mentioned earlier, Django doesn’t actually require a database. If you just want to use it to serve dynamic pages that don’t hit a database, that’s perfectly fine.
With that said, bear in mind that some of the extra tools bundled with Django do require a database, so if you choose not to use a database, you’ll miss out on those features. (We highlight these features throughout this book.)
Starting a Project¶
Once you’ve installed Python, Django and (optionally) your database server/library, you can take the first step in developing a Django application by creating a project.
A project is a collection of settings for an instance of Django, including database configuration, Django-specific options and application-specific settings.
If this is your first time using Django, you’ll have to take care of some
initial setup. Create a new directory to start working in, perhaps something
Where Should This Directory Live?
If your background is in PHP, you’re probably used to putting code under the
Web server’s document root (in a place such as
/var/www). With Django,
you don’t do that. It’s not a good idea to put any of this Python code
within your Web server’s document root, because in doing so you risk the
possibility that people will be able to view your raw source code over the
Web. That’s not good.
Put your code in some directory outside of the document root.
Change into the directory you created, and run the command
django-admin.py startproject mysite. This will create a
directory in your current directory.
django-admin.py should be on your system path if you installed Django
If you’re using trunk, you’ll find
djtrunk/django/bin. Because you’ll be using
often, consider adding it to your system path. On Unix, you can do so by
/usr/local/bin, using a command such as
sudo ln -s
/path/to/django/bin/django-admin.py /usr/local/bin/django-admin.py. On
Windows, you’ll need to update your
PATH environment variable.
If you installed Django from a packaged version for your Linux
django-admin.py might be called
If you see a “permission denied” message when running
django-admin.py startproject, you’ll need to change the file’s permissions.
To do this, navigate to the directory where
django-admin.py is installed
cd /usr/local/bin) and run the command
chmod +x django-admin.py.
startproject command creates a directory containing four files:
mysite/ manage.py mysite/ __init__.py settings.py urls.py wsgi.py
These files are as follows:
mysite/: The outer
mysitedirectory is just a container for your project. It’s name is does not matter to Django; you can rename it to anything you’d like.
manage.py: A command-line utility that lets you interact with this Django project in various ways. Type
python manage.py helpto get a feel for what it can do. You should never have to edit this file; it’s created in this directory purely for convenience.
- The inner
mysite/directory is teh actual Python package for your project. It’s name is the Python package name you’ll need to import anything inside it (e.g import mysite.settings).
mysite/__init__.py: A file required for Python to treat the
mysitedirectory as a package (i.e., a group of Python modules). It’s an empty file, and generally you won’t add anything to it.
mysite/settings.py: Settings/configuration for this Django project. Take a look at it to get an idea of the types of settings available, along with their default values.
mysite/urls.py: The URLs for this Django project. Think of this as the “table of contents” of your Django-powered site. At the moment, it’s empty.
mysite/wsgi.py: An entry-point for WSGI-compatible webservers to serve your project.
Despite their small size, these files already constitute a working Django application.
Running the Development Server¶
For some more post-installation positive feedback, let’s run the Django development server to see our barebones application in action.
The Django development server (also called the “runserver” after the command that launches it) is a built-in, lightweight Web server you can use while developing your site. It’s included with Django so you can develop your site rapidly, without having to deal with configuring your production server (e.g., Apache) until you’re ready for production. The development server watches your code and automatically reloads it, making it easy for you to change your code without needing to restart anything.
To start the server, change into your project directory (
cd mysite), if you
haven’t already, and run this command:
python manage.py runserver
You’ll see something like this:
Validating models... 0 errors found. Django version 1.0, using settings 'mysite.settings' Development server is running at http://127.0.0.1:8000/ Quit the server with CONTROL-C.
This launches the server locally, on port 8000, accessible only to connections from your own computer. Now that it’s running, visit http://127.0.0.1:8000/ with your Web browser. You’ll see a “Welcome to Django” page shaded in a pleasant pastel blue. It worked!
One final, important note about the development server is worth mentioning before proceeding. Although this server is convenient for development, resist the temptation to use it in anything resembling a production environment. The development server can handle only a single request at a time reliably, and it has not gone through a security audit of any sort. When the time comes to launch your site, see Chapter 12 for information on how to deploy Django.
Changing the Development Server’s Host or Port
By default, the
runserver command starts the development server on port
8000, listening only for local connections. If you want to change the
server’s port, pass it as a command-line argument:
python manage.py runserver 8080
By specifying an IP address, you can tell the server to allow non-local
connections. This is especially helpful if you’d like to share a
development site with other members of your team. The IP address
0.0.0.0 tells the server to listen on any network interface:
python manage.py runserver 0.0.0.0:8000
When you’ve done this, other computers on your local network will be able to view your Django site by visiting your IP address in their Web browsers, e.g., http://192.168.1.103:8000/ . (Note that you’ll have to consult your network settings to determine your IP address on the local network. Unix users, try running “ifconfig” in a command prompt to get this information. Windows users, try “ipconfig”.)