Favorite Django Tips & Features?

Question

I'm just going to start with a tip from myself :)

Use os.path.dirname() in settings.py to avoid hardcoded dirnames.

Don't hardcode path's in your settings.py if you want to run your project in different locations. Use the following code in settings.py if your templates and static files are located within the Django project directory:

# settings.py
import os
PROJECT_DIR = os.path.dirname(__file__)
...
STATIC_DOC_ROOT = os.path.join(PROJECT_DIR, "static")
...
TEMPLATE_DIRS = (
    os.path.join(PROJECT_DIR, "templates"),
)

Credits: I got this tip from the screencast 'Django From the Ground Up'.

Install Django Command Extensions and pygraphviz and then issue the following command to get a really nice looking Django model visualization:

./manage.py graph_models -a -g -o my_project.png

Use django-annoying's render_to decorator instead of render_to_response.

@render_to('template.html')
def foo(request):
    bars = Bar.objects.all()
    if request.user.is_authenticated():
        return HttpResponseRedirect("/some/url/")
    else:
        return {'bars': bars}

# equals to
def foo(request):
    bars = Bar.objects.all()
    if request.user.is_authenticated():
        return HttpResponseRedirect("/some/url/")
    else:
        return render_to_response('template.html',
                              {'bars': bars},
                              context_instance=RequestContext(request))

Edited to point out that returning an HttpResponse (such as a redirect) will short circuit the decorator and work just as you expect.

There's a set of custom tags I use all over my site's templates. Looking for a way to autoload it (DRY, remember?), I found the following:

from django import template
template.add_to_builtins('project.app.templatetags.custom_tag_module')

If you put this in a module that's loaded by default (your main urlconf for instance), you'll have the tags and filters from your custom tag module available in any template, without using {% load custom_tag_module %}.

The argument passed to template.add_to_builtins() can be any module path; your custom tag module doesn't have to live in a specific application. For example, it can also be a module in your project's root directory (eg. 'project.custom_tag_module').

Virtualenv + Python = life saver if you are working on multiple Django projects and there is a possibility that they all don't depend on the same version of Django/an application.

Don't hard-code your URLs!

Use url names instead, and the reverse function to get the URL itself.

When you define your URL mappings, give names to your URLs.

urlpatterns += ('project.application.views'
   url( r'^something/$', 'view_function', name="url-name" ),
   ....
)

Make sure the name is unique per URL.

I usually have a consistent format "project-appplication-view", e.g. "cbx-forum-thread" for a thread view.

UPDATE (shamelessly stealing ayaz's addition):

This name can be used in templates with the url tag.