Extention String returning

[Tuvas]

I have been writing a program that is designed to return an 8 byte
string from C to Python. Occasionally one or more of these bytes will
be null, but the size of it will always be known. How can I write an
extention module that will return the correct bytes, and not just until
the null? I would think there would be a fairly  easy way to do this,
but, well... Thanks!