Fixed #13452 - Document that regroup can be used with any template lookup. Thanks shacker for the suggestion and draft patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15108 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/ref/templates/builtins.txt

@@ -800,6 +800,27 @@ filter, if your data is in a list of dictionaries::
 
     {% regroup people|dictsort:"gender" by gender as gender_list %}
 
+
+Grouping on other properties
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Any valid template lookup is a legal grouping attribute for the regroup
+tag, including methods, attributes, dictionary keys and list items. For
+example, if the "gender" field is a foreign key to a class with
+an attribute "description," you could use::
+
+    {% regroup people by gender.description as gender_list %}
+
+Or, if ``gender`` is a field with ``choices``, it will have a
+:meth:`~django.db.models.Model.get_FOO_display` method available as an
+attribute, allowing  you to group on the display string rather than the
+``choices`` key::
+
+    {% regroup people by get_gender_display as gender_list %}
+
+``{{ gender.grouper }}`` will now display the value fields from the
+``choices`` set rather than the keys.
+
 .. templatetag:: spaceless
 
 spaceless