Stopped iterating on INSTALLED_APPS.

Used the app cache's get_app_configs() method instead.

django/template/base.py

@@ -6,6 +6,7 @@ from importlib import import_module
 from inspect import getargspec, getcallargs
 
 from django.conf import settings
+from django.core.apps import app_cache
 from django.template.context import (BaseContext, Context, RequestContext,  # NOQA: imported for backwards compatibility
     ContextPopException)
 from django.utils.itercompat import is_iterable
@@ -1302,9 +1303,12 @@ def get_templatetags_modules():
         # Populate list once per process. Mutate the local list first, and
         # then assign it to the global name to ensure there are no cases where
         # two threads try to populate it simultaneously.
-        for app_module in ['django'] + list(settings.INSTALLED_APPS):
+
+        templatetags_modules_candidates = ['django.templatetags']
+        templatetags_modules_candidates += ['%s.templatetags' % app_config.name
+            for app_config in app_cache.get_app_configs()]
+        for templatetag_module in templatetags_modules_candidates:
             try:
-                templatetag_module = '%s.templatetags' % app_module
                 import_module(templatetag_module)
                 _templatetags_modules.append(templatetag_module)
             except ImportError:

django/template/loaders/app_directories.py

@@ -3,12 +3,11 @@ Wrapper for loading templates from "templates" directories in INSTALLED_APPS
 packages.
 """
 
-from importlib import import_module
 import os
 import sys
 
 from django.conf import settings
-from django.core.exceptions import ImproperlyConfigured
+from django.core.apps import app_cache
 from django.template.base import TemplateDoesNotExist
 from django.template.loader import BaseLoader
 from django.utils._os import safe_join
@@ -18,12 +17,8 @@ from django.utils import six
 if six.PY2:
     fs_encoding = sys.getfilesystemencoding() or sys.getdefaultencoding()
 app_template_dirs = []
-for app in settings.INSTALLED_APPS:
-    try:
-        mod = import_module(app)
-    except ImportError as e:
-        raise ImproperlyConfigured('ImportError %s: %s' % (app, e.args[0]))
-    template_dir = os.path.join(os.path.dirname(mod.__file__), 'templates')
+for app_config in app_cache.get_app_configs():
+    template_dir = os.path.join(app_config.path, 'templates')
     if os.path.isdir(template_dir):
         if six.PY2:
             template_dir = template_dir.decode(fs_encoding)

django/template/loaders/eggs.py

@@ -7,6 +7,7 @@ except ImportError:
     resource_string = None
 
 from django.conf import settings
+from django.core.apps import app_cache
 from django.template.base import TemplateDoesNotExist
 from django.template.loader import BaseLoader
 from django.utils import six
@@ -23,12 +24,12 @@ class Loader(BaseLoader):
         """
         if resource_string is not None:
             pkg_name = 'templates/' + template_name
-            for app in settings.INSTALLED_APPS:
+            for app_config in app_cache.get_app_configs():
                 try:
-                    resource = resource_string(app, pkg_name)
+                    resource = resource_string(app_config.name, pkg_name)
                 except Exception:
                     continue
                 if six.PY2:
                     resource = resource.decode(settings.FILE_CHARSET)
-                return (resource, 'egg:%s:%s' % (app, pkg_name))
+                return (resource, 'egg:%s:%s' % (app_config.name, pkg_name))
         raise TemplateDoesNotExist(template_name)