django-configurations

django-configurations eases Django project configuration by relying on the composability of Python classes. It extends the notion of Django’s module based settings loading with well established object oriented programming patterns.

Quickstart

Install django-configurations:

pip install django-configurations

Then subclass the included configurations.Configuration class in your project’s settings.py or any other module you’re using to store the settings constants, e.g.:

# mysite/settings.py

from configurations import Configuration

class Dev(Configuration):
    DEBUG = True

Set the DJANGO_CONFIGURATION environment variable to the name of the class you just created, e.g. in bash:

export DJANGO_CONFIGURATION=Dev

and the DJANGO_SETTINGS_MODULE environment variable to the module import path as usual, e.g. in bash:

export DJANGO_SETTINGS_MODULE=mysite.settings

Alternatively supply the --configuration option when using Django management commands along the lines of Django’s default --settings command line option, e.g.:

python manage.py runserver --settings=mysite.settings --configuration=Dev

To enable Django to use your configuration you now have to modify your manage.py or wsgi.py script to use django-configurations’s versions of the appropriate starter functions, e.g. a typical manage.py using django-configurations would look like this:

 #!/usr/bin/env python

 import os
 import sys

 if __name__ == "__main__":
     os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'mysite.settings')
     os.environ.setdefault('DJANGO_CONFIGURATION', 'Dev')

     from configurations.management import execute_from_command_line

     execute_from_command_line(sys.argv)

Notice in line 10 we don’t use the common tool django.core.management.execute_from_command_line but instead configurations.management.execute_from_command_line.

The same applies to your wsgi.py file, e.g.:

 import os

 os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'mysite.settings')
 os.environ.setdefault('DJANGO_CONFIGURATION', 'Dev')

 from configurations.wsgi import get_wsgi_application

 application = get_wsgi_application()

Here we don’t use the default django.core.wsgi.get_wsgi_application function but instead configurations.wsgi.get_wsgi_application.

That’s it! You can now use your project with manage.py and your favorite WSGI enabled server.

Project templates

Don’t miss the Django project templates pre-configured with django-configurations to simplify getting started with new Django projects.

Wait, what?

django-configurations helps you organize the configuration of your Django project by providing the glue code to bridge between Django’s module based settings system and programming patterns like mixins, facades, factories and adapters that are useful for non-trivial configuration scenarios.

It allows you to use the native abilities of Python inheritance without the side effects of module level namespaces that often lead to the unfortunate use of the from foo import * anti-pattern.

Okay, how does it work?

Any subclass of the configurations.Configuration class will automatically use the values of its class and instance attributes (including properties and methods) to set module level variables of the same module – that’s how Django will interface to the django-configurations based settings during startup and also the reason why it requires you to use its own startup functions.

That means when Django starts up django-configurations will have a look at the DJANGO_CONFIGURATION environment variable to figure out which class in the settings module (as defined by the DJANGO_SETTINGS_MODULE environment variable) should be used for the process. It then instantiates the class defined with DJANGO_CONFIGURATION and copies the uppercase attributes to the module level variables.

New in version 0.2.

Alternatively you can use the --configuration command line option that django-configurations adds to all Django management commands. Behind the scenes it will simply set the DJANGO_CONFIGURATION environement variable so this is purely optional and just there to compliment the default --settings option that Django adds if you prefer that instead of setting environment variables.

But isn’t that magic?

Yes, it looks like magic, but it’s also maintainable and non-intrusive. No monkey patching is needed to teach Django how to load settings via django-configurations because it uses Python import hooks (PEP 302) behind the scenes.

Further documentation

• Usage patterns
  • Server specific settings
  • Global settings defaults
  • Configuration mixins
  • Pristine methods
  • Setup methods
• Values
  • Overview
  • Environment variables
    • Default behavior
    • Disabling environment variables
    • Custom environment variable names
    • Custom environment variable prefixes
  • Value class
  • Built-ins
    • Type values
    • Validator values
    • URL-based values
    • Other values
    • Value mixins
• Cookbook
  • Envdir
  • Project templates
    • Django 1.5.x
    • Django 1.6.x
  • Celery
  • iPython notebooks
  • FastCGI
• Changelog
  • v0.6 (2013-09-19)
  • v0.5.1 (2013-09-12)
  • v0.5 (2013-09-09)
  • v0.4 (2013-09-03)
  • v0.3 (2013-05-15)
  • v0.2.1 (2013-04-11)
  • v0.2 (2013-03-27)
  • v0.1 (2012-07-21)

Alternatives

Many thanks to those project that have previously solved these problems:

• The Pinax project for spearheading the efforts to extend the Django project metaphor with reusable project templates and a flexible configuration environment.
• django-classbasedsettings by Matthew Tretter for being the immediate inspiration for django-configurations.

Bugs and feature requests

As always your mileage may vary, so please don’t hesitate to send feature requests and bug reports:

https://github.com/jezdez/django-configurations/issues

Thanks! Feel free to leave a tip, too:

https://www.gittip.com/jezdez/