C[omp]ute

From: "andrew cooke" <andrew@...>

Date: Fri, 26 Jun 2009 15:46:17 -0400 (CLT)

I couldn't find thsi documented, apart from obliquely in bug report -
http://code.djangoproject.com/ticket/2289 - but here's what you do...

Initially, in a simple app, Django assumes that your model classes live in
"models.py".  This location is read by, for example, the manager.

However, that soon becomes cluttered, and the "right way" to handle this
in Python would be to use a package (directory) rather than a single
module (file).

If you do that, and are not careful, all hell breaks loose :o(

Here's how to make it work:

- Call the directory/package "models"
- Inside that package, put all your code.
- On each model set the Meta attribute app_label to the app name
- Create an __init__.py file inside the package
- In the __init__.py file:
-- Import all your models
-- Declare them using __all__

So, for example, if I have a model class Foo in blah.models.foo (ie
blah/models/foo.py) and a model class Bar in blah.models.bar, then in
__init__.py I have:

  from blah.models.foo import Foo
  from blah.models.bar import Bar

  __all__ = ['Foo', 'Bar']


And the declaration of Foo looks like:

  class Foo(Model):
    class Meta:
      app_label = 'blah'
    ...

In this way you end up with the objects still "looking as if" they are in
blah.models (in other parts of your code you can import directly from
there) and with the correct meta data for the manager to find and use
them.

Andrew