[Zope] Accessing File Object Contents in Python Script

Does anyone know how to access the contents of a File object (i.e., the file itself) from within a python script. o.file or o.contents doesn't work. The idea is to be able to run the file contents through some post-loading processing on the contents of the file. Incidentally, the Zope API only has getContentType() and getSize(), not the document itself. If you happen to know where in the Zope source this might be found, I'd be happy to know. grepping "file" is a slow and arduous way to go. Thanks everyone, Ron