Documented django.setup().

    :exc:`ValueError` when called with a single argument that doesn't contain

    exactly one dot.

Initialization process

======================

How applications are loaded

---------------------------

When Django starts, :func:`django.setup()` is responsible for populating the

application registry.

.. currentmodule:: django

.. function:: setup()

    Configures Django by:

    * Loading the settings.

    * Setting up logging.

    * Initializing the application registry.

    This function is called automatically:

    * When running an HTTP server via Django's WSGI support.

    * When invoking a management command.

    It must be called explicitly in other cases, for instance in plain Python

    scripts.

.. currentmodule:: django.apps

The application registry is initialized in three stages. At each stage, Django

processes all applications in the order of :setting:`INSTALLED_APPS`.

#. First Django imports each item in :setting:`INSTALLED_APPS`.

   If it's an application configuration class, Django imports the root package

   of the application, defined by its :attr:`~AppConfig.name` attribute. If

   it's a Python package, Django creates a default application configuration.

   *At this stage, your code shouldn't import any models!*

   In other words, your applications' root packages and the modules that

   define your application configuration classes shouldn't import any models,

   even indirectly.

   Strictly speaking, Django allows importing models once their application

   configuration is loaded. However, in order to avoid needless constraints on

   the order of :setting:`INSTALLED_APPS`, it's strongly recommended not

   import any models at this stage.

#. Then Django attempts to import the ``models`` submodule of each application,

   if there is one.

   You must define or import all models in your application's ``models.py`` or

   ``models/__init__.py``. Otherwise, the application registry may not be fully

   populated at this point, which could cause the ORM to malfunction.

#. Finally Django runs the :meth:`~AppConfig.ready()` method of each application

   configuration.

.. _applications-troubleshooting:

Troubleshooting

===============

---------------

Django loads application configurations and models as soon as it starts. Here

are some common problems you may encounter:

Here are some common problems that you may encounter during initialization:

* ``RuntimeError: App registry isn't ready yet.`` This happens when importing

  an application configuration or a models module triggers code that depends

  the :setting:`AUTH_USER_MODEL` setting to reference the User model at import

  time.

  This exception also happens if you forget to call :func:`django.setup()` in

  a standalone Python script.

* ``ImportError: cannot import name ...`` This happens if the import sequence

  ends up in a loop.

* It sets the :envvar:`DJANGO_SETTINGS_MODULE` environment variable so that

  it points to your project's ``settings.py`` file.

* It calls ``django.setup()`` to initialize various internals of Django.

* It calls :func:`django.setup()` to initialize various internals of Django.

.. versionadded:: 1.7

    ``django.setup()`` didn't exist in previous versions of Django.

    :func:`django.setup()` didn't exist in previous versions of Django.

The ``django-admin.py`` script should be on your system path if you installed

Django via its ``setup.py`` utility. If it's not on your path, you can find it