FAQ: Using Django

Why do I get an error about importing DJANGO_SETTINGS_MODULE?

Make sure that:

  • The environment variable DJANGO_SETTINGS_MODULE is set to a fully-qualified Python module (i.e. “mysite.settings”).

  • Said module is on sys.path (import mysite.settings should work).

  • The module doesn’t contain syntax errors (of course).

  • If you’re using mod_python but not using Django’s request handler, you’ll need to work around a mod_python bug related to the use of SetEnv; before you import anything from Django you’ll need to do the following:

    os.environ.update(req.subprocess_env)
    

    (where req is the mod_python request object).

I can’t stand your template language. Do I have to use it?

We happen to think our template engine is the best thing since chunky bacon, but we recognize that choosing a template language runs close to religion. There’s nothing about Django that requires using the template language, so if you’re attached to ZPT, Cheetah, or whatever, feel free to use those.

Do I have to use your model/database layer?

Nope. Just like the template system, the model/database layer is decoupled from the rest of the framework.

The one exception is: If you use a different database library, you won’t get to use Django’s automatically-generated admin site. That app is coupled to the Django database layer.

How do I use image and file fields?

Using a FileField or an ImageField in a model takes a few steps:

  1. In your settings file, you’ll need to define MEDIA_ROOT as the full path to a directory where you’d like Django to store uploaded files. (For performance, these files are not stored in the database.) Define MEDIA_URL as the base public URL of that directory. Make sure that this directory is writable by the Web server’s user account.
  2. Add the FileField or ImageField to your model, making sure to define the upload_to option to tell Django to which subdirectory of MEDIA_ROOT it should upload files.
  3. All that will be stored in your database is a path to the file (relative to MEDIA_ROOT). You’ll most likely want to use the convenience url attribute provided by Django. For example, if your ImageField is called mug_shot, you can get the absolute path to your image in a template with {{ object.mug_shot.url }}.

How do I make a variable available to all my templates?

Sometimes your templates just all need the same thing. A common example would be dynamically-generated menus. At first glance, it seems logical to simply add a common dictionary to the template context.

The correct solution is to use a RequestContext. Details on how to do this are here: Subclassing Context: RequestContext.