Kill execfile(), use exec() instead
diff --git a/Lib/optparse.py b/Lib/optparse.py
index 84a6abd..bae1050 100644
--- a/Lib/optparse.py
+++ b/Lib/optparse.py
@@ -874,7 +874,7 @@
 
     def read_file(self, filename, mode="careful"):
         vars = {}
-        execfile(filename, vars)
+        exec(open(filename).read(), vars)
         self._update(vars, mode)
 
     def ensure_value(self, attr, value):