[Python3] Reading a binary file and wrtiting the bytes verbatim in an utf-8 file

[fab at slick.airforce-one.org]

Hello.

I have to read the contents of a binary file (a PNG file exactly), and
dump it into an RTF file.

The RTF-file has been opened with codecs.open in utf-8 mode.

As I expected, the utf-8 decoder chokes on some combinations of bits;
how can I tell python to dump the bytes as they are, without
interpreting them?

Thanks.

-- 
Fabrice DELENTE