#4578: fix has_key() usage in compiler package.
diff --git a/Lib/compiler/misc.py b/Lib/compiler/misc.py
index 8d91770..588c7fb 100644
--- a/Lib/compiler/misc.py
+++ b/Lib/compiler/misc.py
@@ -14,13 +14,13 @@
     def __len__(self):
         return len(self.elts)
     def __contains__(self, elt):
-        return self.elts.has_key(elt)
+        return elt in self.elts
     def add(self, elt):
         self.elts[elt] = elt
     def elements(self):
         return self.elts.keys()
     def has_elt(self, elt):
-        return self.elts.has_key(elt)
+        return elt in self.elts
     def remove(self, elt):
         del self.elts[elt]
     def copy(self):