Django template loader that allows for `namespaced` loading of templates.

namespaced_app_directories.py

"""
Wrapper for loading templates from "templates" directories in INSTALLED_APPS
packages, prefixed by the appname for namespacing.

This loader finds `appname/templates/index.html` when looking for something
of the form `appname/index.html`.
"""

from django.template import TemplateDoesNotExist
from django.template.loaders.app_directories import app_template_dirs, Loader as BaseAppLoader

class Loader(BaseAppLoader):
    '''
    Modified AppDirectory Template Loader that allows namespacing templates
    with the name of their app, without requiring an extra subdirectory
    in the form of `appname/templates/appname`.
    '''
    def load_template_source(self, template_name, template_dirs=None):
        try:
            app_name, template_path = template_name.split('/', 1)
        except ValueError:
            raise TemplateDoesNotExist(template_name)

        if not template_dirs:
            template_dirs = (d for d in app_template_dirs if
                    d.endswith('/%s/templates' % app_name))

        return iter(super(Loader, self).load_template_source(template_path,
                template_dirs))

OK, here's what I wound up with. It's working with Django 1.8 and Python 2.7 (Markdown code highlighting doesn't work right with this much text):

############################
from django.template import TemplateDoesNotExist
from django.template.loaders.app_directories import get_app_template_dirs, Loader as BaseAppLoader
app_template_dirs = get_app_template_dirs('templates')
from os import sep

class Loader(BaseAppLoader):

def load_template_source(self, template_name, template_dirs=None):
    try:
        app_name, template_path = template_name.split(sep, 1)
    except ValueError:
        raise TemplateDoesNotExist(template_name)

    if not template_dirs:
        if app_name == 'registration':
            template_dirs = (d for d in app_template_dirs if
                    d.endswith( '{}{}{}templates'.format(sep, 'admin', sep) ) )
        elif app_name == 'admin_doc':
            template_dirs = (d for d in app_template_dirs if
                    d.endswith( '{}{}{}templates'.format(sep, 'admindocs', sep) ) )
        else:
            template_dirs = (d for d in app_template_dirs if
                    d.endswith( '{}{}{}templates'.format(sep, app_name, sep) ) )

    if app_name in [u'admin', u'auth', u'admindocs']: template_path = app_name + sep + template_path

    if app_name == 'admin_doc': template_path = 'admin_doc' + sep + template_path
    if app_name == 'registration': template_path = 'registration' + sep + template_path

    return iter(super(Loader, self).load_template_source(template_path, template_dirs))

########################

So things got squirrelly, due to all of the changes that were necessary to make admin work, and also, from the admin GUI, the Documentation and Change Password links to work. Alternatively, the code as I left it after my first comment above can work if in your TEMPLATES list in settings.py you put for the dict 'DIRS' key entry a listing of the admin, admindocs and auth template directories, such as:

        '/pathto/djangoenv/local/lib/python2.7/site-packages/django/contrib/admin/templates',
        '/pathto/djangoenv/local/lib/python2.7/site-packages/django/contrib/auth/templates',
        '/pathto/djangoenv/local/lib/python2.7/site-packages/django/contrib/admindocs/templates',

But those paths being installation-specific, for now I'm sticking with the code of this comment.