django1/django/contrib/admin/__init__.py

# ACTION_CHECKBOX_NAME is unused, but should stay since its import from here
# has been referenced in documentation.
from django.contrib.admin.helpers import ACTION_CHECKBOX_NAME
from django.contrib.admin.options import ModelAdmin, HORIZONTAL, VERTICAL
from django.contrib.admin.options import StackedInline, TabularInline
from django.contrib.admin.sites import AdminSite, site
from django.contrib.admin.filters import (ListFilter, SimpleListFilter,
    FieldListFilter, BooleanFieldListFilter, RelatedFieldListFilter,
    ChoicesFieldListFilter, DateFieldListFilter, AllValuesFieldListFilter)


def autodiscover():
    """
    Auto-discover INSTALLED_APPS admin.py modules and fail silently when
    not present. This forces an import on them to register any admin bits they
    may want.
    """

    import copy
    from importlib import import_module
    from django.conf import settings
    from django.utils.module_loading import module_has_submodule

    for app in settings.INSTALLED_APPS:
        mod = import_module(app)
        # Attempt to import the app's admin module.
        try:
            before_import_registry = copy.copy(site._registry)
            import_module('%s.admin' % app)
        except:
            # Reset the model registry to the state before the last import as
            # this import will have to reoccur on the next request and this
            # could raise NotRegistered and AlreadyRegistered exceptions
            # (see #8245).
            site._registry = before_import_registry

            # Decide whether to bubble up this error. If the app just
            # doesn't have an admin module, we can ignore the error
            # attempting to import it, otherwise we want it to bubble up.
            if module_has_submodule(mod, 'admin'):
                raise