#2503 make singletons compared with "is" not == or !=
Thanks to Wummel for the patch
diff --git a/Lib/idlelib/AutoComplete.py b/Lib/idlelib/AutoComplete.py
index e1549be..bed2b8c 100644
--- a/Lib/idlelib/AutoComplete.py
+++ b/Lib/idlelib/AutoComplete.py
@@ -35,10 +35,9 @@
                                    "popupwait", type="int", default=0)
 
     def __init__(self, editwin=None):
-        if editwin == None:  # subprocess and test
-            self.editwin = None
-            return
         self.editwin = editwin
+        if editwin is None:  # subprocess and test
+            return
         self.text = editwin.text
         self.autocompletewindow = None