Widen test to support unicode.
diff --git a/Lib/idlelib/run.py b/Lib/idlelib/run.py
index 82db38a..9389a2b 100644
--- a/Lib/idlelib/run.py
+++ b/Lib/idlelib/run.py
@@ -263,7 +263,7 @@
         return setattr(self.rpc, name, value)
 
     def write(self, s):
-        if not isinstance(s, str):
+        if not isinstance(s, basestring):
             raise TypeError('must be str, not ' + type(s).__name__)
         return self.rpc.write(s)