Any Python modules for manipulating JFIF file contents?

[Kenneth McDonald]

Warning: this post may display my utter ignorance of image file format
facts.

As part of a photo album program I'm working on, I'd like to be able
to work with the metadata in JPEG files, which I understand are
really JFIF files holding jpg data. Do any Python modules permit
me to do this? I looked at PIL, but it seemed to operatre at a
higher level, i.e. hiding the file-level implementation details.

At the least I'd like to be able to :

1) Extract the metadata (comments, thumbnails, etc)
2) Extract the raw JPEG data (since I want to experiment with
combining multiple images into a single 'album' file using
gdbm file.)

Writing would be nice, but is not necessary.

Failing a Python module, can anyone suggest the best library
to look at to wrap in a module? 

Thanks,
Ken McDonald