Anyone could recommend a good guide/tutorial/article with tips/guidelines in how to organize and partition a large Django project?
I'm looking for advices in what to do when you need to start factorizing the initial unique files (models.py, urls.py, views.py) and working with more than a few dozens of entities.
Each "application" should be small -- a single reusable entity plus a few associated tables. We have about 5 plus/minus 2 tables per application model. Most of our half-dozen applications are smaller than 5 tables. One has zero tables in the model.
Each application should be designed to be one reusable concept. In our case, each application is a piece of the overall site; the applications could be removed and replaced separately.
Indeed, that's our strategy. As our requirements expand and mature, we can remove and replace applications independently from each other.
It's okay to have applications depend on each other. However, the dependency has to be limited to the obvious things like "models" and "forms". Also, applications can depend on the names in each other's URL's. Consequently, your named URL's must have a form like "application-view" so the reverse function or the {% url %} tag can find them properly.
Each application should contain it's own batch commands (usually via a formal Command that can be found by the django-admin script.
Finally, anything that's more complex than a simple model or form that's shared probably doesn't belong to either application, but needs to be a separate shared library. For example, we use XLRD, but wrap parts of it in our own class so it's more like the built-in csv module. This wrapper for XLRD isn't a proper part of any one application, to it's a separate module, outside the Django applications.
I've found it to be helpful to take a look at large open-source Django projects and take note of how that project does it. Django's site has a good list of open-source projects:
http://code.djangoproject.com/wiki/DjangoResources#Open-SourceDjangoprojects
As does Google (although most of these are smaller add-in template tags and Middleware:
http://code.google.com/hosting/search?q=label:django
Of course, just because one project does it one way does not mean that that way is The Right Way (or The Wrong Way). Some of those projects are more successful than others.
In the end, the only way to really learn what works and doesn't work is to try it out yourself. All the tips and hints in the world wont help unless you try it out yourself, but they may help you get started in the right direction.