Writing new codecs

[Brian Quinlan]

I just finished writing a modified UTF-7 encoder/decoder in Python and
am planning on contributing it back. 

My question is regarding form: should new codecs be written in C or
Python? 

AFAIK, Python does not currently include any codecs written in Python
(I'm not counting the character mapping ones or the trivial wrappers
around C code). Is this because the current codecs are all "important"
and future codecs should be implemented elsewhere to avoid adding too
much junk to codecmodule.c and unicodeobject.c? 

Or is the pattern of providing the actual implementation in
unicodeobject.c going to continue?

Cheers,
Brian