Ticket #12820: mergedict_patch.diff

django/utils/datastructures.py

@@ +1 @@
+import itertools
 from types import GeneratorType
 
 from django.utils.copycompat import deepcopy
@@ -37 +38 @@
                 return dict_.getlist(key)
         return []
 
+    def __iter__(self):
+        seen = set()
+        for key in itertools.chain.from_iterable(self.dicts):
+            if key not in seen:
+                seen.add(key)
+                yield key
+
     def items(self):
         item_list = []
         for dict_ in self.dicts:

tests/regressiontests/datastructures/tests.py

@@ -34 +34 @@
 >>> mm.getlist('undefined')
 []
 
+MergeDict supports iterating on keys
+>>> [(k,mm.getlist(k)) for k in mm]
+[('key2', ['value2', 'value3']), ('key1', ['value1']), ('key4', ['value5', 'value6'])]
+
 ### MultiValueDict ##########################################################
 
 >>> d = MultiValueDict({'name': ['Adrian', 'Simon'], 'position': ['Developer']})