make OMD picklable under py3, fixes #337

mahmoud · Apr 18, 2023 · 504b9d4 · 504b9d4
1 parent f892a2b
commit 504b9d4
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Showing 2 changed files with 15 additions and 1 deletion.
diff --git a/boltons/dictutils.py b/boltons/dictutils.py
@@ -173,13 +173,17 @@ class OrderedMultiDict(dict):
        behavior, just use :meth:`~OrderedMultiDict.todict()`.
 
     """
+    def __new__(cls, *a, **kw):
+        ret = super(OrderedMultiDict, cls).__new__(cls)
+        ret._clear_ll()
+        return ret 
+
     def __init__(self, *args, **kwargs):
         if len(args) > 1:
             raise TypeError('%s expected at most 1 argument, got %s'
                             % (self.__class__.__name__, len(args)))
         super(OrderedMultiDict, self).__init__()
 
-        self._clear_ll()
         if args:
             self.update_extend(args[0])
         if kwargs:

diff --git a/tests/test_dictutils.py b/tests/test_dictutils.py
@@ -74,6 +74,16 @@ def test_copy():
     return
 
 
+def test_omd_pickle():
+    import pickle
+
+    empty = OMD()
+    assert pickle.loads(pickle.dumps(empty)) == empty
+
+    nonempty = OMD([('a', 1), ('b', 2)])
+    assert pickle.loads(pickle.dumps(nonempty)) == nonempty
+
+
 def test_clear():
     for itemset in _ITEMSETS:
         omd = OMD(itemset)