Fixed #25670 -- Allowed dictsort to sort a list of lists.

Thanks Tim Graham for the review.

django/template/defaultfilters.py

@@ -5,6 +5,7 @@ import random as random_module
 import re
 from decimal import ROUND_HALF_UP, Context, Decimal, InvalidOperation
 from functools import wraps
+from operator import itemgetter
 from pprint import pformat
 
 from django.utils import formats, six
@@ -510,6 +511,32 @@ def striptags(value):
 # LISTS           #
 ###################
 
+def _property_resolver(arg):
+    """
+    When arg is convertible to float, behave like operator.itemgetter(arg)
+    Otherwise, behave like Variable(arg).resolve
+
+    >>> _property_resolver(1)('abc')
+    'b'
+    >>> _property_resolver('1')('abc')
+    Traceback (most recent call last):
+    ...
+    TypeError: string indices must be integers
+    >>> class Foo:
+    ...     a = 42
+    ...     b = 3.14
+    ...     c = 'Hey!'
+    >>> _property_resolver('b')(Foo())
+    3.14
+    """
+    try:
+        float(arg)
+    except ValueError:
+        return Variable(arg).resolve
+    else:
+        return itemgetter(arg)
+
+
 @register.filter(is_safe=False)
 def dictsort(value, arg):
     """
@@ -517,7 +544,7 @@ def dictsort(value, arg):
     the argument.
     """
     try:
-        return sorted(value, key=Variable(arg).resolve)
+        return sorted(value, key=_property_resolver(arg))
     except (TypeError, VariableDoesNotExist):
         return ''
 
@@ -529,7 +556,7 @@ def dictsortreversed(value, arg):
     property given in the argument.
     """
     try:
-        return sorted(value, key=Variable(arg).resolve, reverse=True)
+        return sorted(value, key=_property_resolver(arg), reverse=True)
     except (TypeError, VariableDoesNotExist):
         return ''
 

django/views/debug.py

@@ -813,7 +813,7 @@ TECHNICAL_500_TEMPLATE = ("""
                 </tr>
               </thead>
               <tbody>
-                {% for var in frame.vars|dictsort:"0" %}
+                {% for var in frame.vars|dictsort:0 %}
                   <tr>
                     <td>{{ var.0|force_escape }}</td>
                     <td class="code"><pre>{{ var.1 }}</pre></td>
@@ -995,7 +995,7 @@ Exception Value: {{ exception_value|force_escape }}
       </tr>
     </thead>
     <tbody>
-      {% for var in request.META.items|dictsort:"0" %}
+      {% for var in request.META.items|dictsort:0 %}
         <tr>
           <td>{{ var.0 }}</td>
           <td class="code"><pre>{{ var.1|pprint }}</pre></td>
@@ -1017,7 +1017,7 @@ Exception Value: {{ exception_value|force_escape }}
       </tr>
     </thead>
     <tbody>
-      {% for var in settings.items|dictsort:"0" %}
+      {% for var in settings.items|dictsort:0 %}
         <tr>
           <td>{{ var.0 }}</td>
           <td class="code"><pre>{{ var.1|pprint }}</pre></td>
@@ -1107,12 +1107,12 @@ FILES:{% for k, v in request.FILES.items %}
 COOKIES:{% for k, v in request.COOKIES.items %}
 {{ k }} = {{ v|stringformat:"r" }}{% empty %} No cookie data{% endfor %}
 
-META:{% for k, v in request.META.items|dictsort:"0" %}
+META:{% for k, v in request.META.items|dictsort:0 %}
 {{ k }} = {{ v|stringformat:"r" }}{% endfor %}
 {% else %}Request data not supplied
 {% endif %}
 Settings:
-Using settings module {{ settings.SETTINGS_MODULE }}{% for k, v in settings.items|dictsort:"0" %}
+Using settings module {{ settings.SETTINGS_MODULE }}{% for k, v in settings.items|dictsort:0 %}
 {{ k }} = {{ v|stringformat:"r" }}{% endfor %}
 
 {% if not is_email %}