Patch #462635 by Andrew Kuchling correcting bugs in the new
codecs -- the self argument does matter for Python functions (it
does not for C functions which most other codecs use).
diff --git a/Lib/encodings/hex_codec.py b/Lib/encodings/hex_codec.py
index ab7d86f..572ff79 100644
--- a/Lib/encodings/hex_codec.py
+++ b/Lib/encodings/hex_codec.py
@@ -44,8 +44,10 @@
 
 class Codec(codecs.Codec):
 
-    encode = hex_encode
-    decode = hex_decode
+    def encode(self, input,errors='strict'):
+        return hex_encode(input,errors)
+    def decode(self, input,errors='strict'):
+        return hex_decode(input,errors)
 
 class StreamWriter(Codec,codecs.StreamWriter):
     pass