Have the sha module raise a DeprecationWarning as specified in PEP 4.
diff --git a/Lib/sha.py b/Lib/sha.py
index 9d914a9..7e6d7af 100644
--- a/Lib/sha.py
+++ b/Lib/sha.py
@@ -3,6 +3,10 @@
 #  Copyright (C) 2005   Gregory P. Smith (greg@electricrain.com)
 #  Licensed to PSF under a Contributor Agreement.
 
+import warnings
+warnings.warn("the sha module is deprecated; use the hashlib module instead",
+                DeprecationWarning, 2)
+
 from hashlib import sha1 as sha
 new = sha