Regular expression parsing a binary file?

I have a file which mixes binary data and text data. I want to parse it through a regular expression, but I get this error:

TypeError: can't use a string pattern on a bytes-like object

I'm guessing that message means that Python doesn't want to parse binary files. I'm opening the file with the "rb" flags.

How can I parse binary files with regular expressions in Python?

EDIT: I'm using Python 3.2.0