Patch# 1258 by Christian Heimes: kill basestring.
I like this because it makes the code shorter! :-)
diff --git a/Lib/test/test_ast.py b/Lib/test/test_ast.py
index 6299123..4883ed5 100644
--- a/Lib/test/test_ast.py
+++ b/Lib/test/test_ast.py
@@ -2,7 +2,7 @@
 import _ast
 
 def to_tuple(t):
-    if t is None or isinstance(t, (basestring, int, int, complex)):
+    if t is None or isinstance(t, (str, int, complex)):
         return t
     elif isinstance(t, list):
         return [to_tuple(e) for e in t]