1 files changed, 6 insertions, 4 deletions
diff --git a/Lib/sets.py b/Lib/sets.py
index 10138fc..bf3ff4d 100644
--- a/Lib/sets.py
+++ b/Lib/sets.py
@@ -197,11 +197,13 @@ class BaseSet(object):
         result = self.__class__()
         data = result._data
         value = True
-        for elt in self:
-            if elt not in other:
+        selfdata = self._data
+        otherdata = other._data
+        for elt in selfdata:
+            if elt not in otherdata:
                 data[elt] = value
-        for elt in other:
-            if elt not in self:
+        for elt in otherdata:
+            if elt not in selfdata:
                 data[elt] = value
         return result