implement missing inequality on WeakSet
diff --git a/Lib/_weakrefset.py b/Lib/_weakrefset.py
index 43f9a6e..990c3a6 100644
--- a/Lib/_weakrefset.py
+++ b/Lib/_weakrefset.py
@@ -171,6 +171,12 @@
return NotImplemented
return self.data == set(ref(item) for item in other)
+ def __ne__(self, other):
+ opposite = self.__eq__(other)
+ if opposite is NotImplemented:
+ return NotImplemented
+ return not opposite
+
def symmetric_difference(self, other):
newset = self.copy()
newset.symmetric_difference_update(other)