--- a/RefactoringRope/ChangeSignatureDialog.py	Wed Mar 08 19:35:56 2017 +0100
+++ b/RefactoringRope/ChangeSignatureDialog.py	Tue Mar 28 19:36:35 2017 +0200
@@ -143,7 +143,7 @@
         if dlg.exec_() == QDialog.Accepted:
             name, default, value = dlg.getData()
             if default:
-                s = "%s = %s" % (name, default)
+                s = "{0} = {1}".format(name, default)
             else:
                 s = name
             itm = QListWidgetItem(s)