Ticket #4506: RegroupNode-groupby.patch

django/template/defaulttags.py

@@ -4 +4 @@
 from django.template import TemplateSyntaxError, VariableDoesNotExist, BLOCK_TAG_START, BLOCK_TAG_END, VARIABLE_TAG_START, VARIABLE_TAG_END, SINGLE_BRACE_START, SINGLE_BRACE_END, COMMENT_TAG_START, COMMENT_TAG_END
 from django.template import get_library, Library, InvalidTemplateLibrary
 from django.conf import settings
+from itertools import groupby
 import sys
 import re
 
@@ -248 +249 @@
         if obj_list == None: # target_var wasn't found in context; fail silently
             context[self.var_name] = []
             return ''
-        output = [] # list of dictionaries in the format {'grouper': 'key', 'list': [list of contents]}
-        for obj in obj_list:
-            grouper = self.expression.resolve(obj, True)
-            # TODO: Is this a sensible way to determine equality?
-            if output and repr(output[-1]['grouper']) == repr(grouper):
-                output[-1]['list'].append(obj)
-            else:
-                output.append({'grouper': grouper, 'list': [obj]})
-        context[self.var_name] = output
+        # list of dictionaries in the format {'grouper': 'key', 'list': [list of contents]}
+        context[self.var_name] = [{'grouper':key, 'list':list(val)} for key, val in
+            groupby(obj_list, lambda v, f=self.expression.resolve: f(v, True))]
         return ''
 
 def include_is_allowed(filepath):