Patch# 1258 by Christian Heimes: kill basestring.
I like this because it makes the code shorter! :-)
diff --git a/Lib/xml/sax/saxutils.py b/Lib/xml/sax/saxutils.py
index a4bcb08..a569c1d 100644
--- a/Lib/xml/sax/saxutils.py
+++ b/Lib/xml/sax/saxutils.py
@@ -272,7 +272,7 @@
     """This function takes an InputSource and an optional base URL and
     returns a fully resolved InputSource object ready for reading."""
 
-    if isinstance(source, basestring):
+    if isinstance(source, str):
         source = xmlreader.InputSource(source)
     elif hasattr(source, "read"):
         f = source