Use types.StringTypes instead of explicit (str, unicode) list
diff --git a/Lib/inspect.py b/Lib/inspect.py
index 38b93bf..2f9511a 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -267,7 +267,7 @@
         doc = object.__doc__
     except AttributeError:
         return None
-    if not isinstance(doc, (str, unicode)):
+    if not isinstance(doc, types.StringTypes):
         return None
     try:
         lines = string.split(string.expandtabs(doc), '\n')