Supply a reduce method for pickling.

rhettinger · rhettinger · commit ff72816b5fad · 2011-01-03T02:44:14.000Z
diff --git a/Lib/collections.py b/Lib/collections.py
@@ -539,6 +539,9 @@ def copy(self):
         'Like dict.copy() but returns a Counter instance instead of a dict.'
         return Counter(self)
 
+    def __reduce__(self):
+        return self.__class__, (dict(self),)
+
     def __delitem__(self, elem):
         'Like dict.__delitem__() but does not raise KeyError for missing values.'
         if elem in self:
