[Zope] Opening a ZOPE file object ?

Is it possible to open a file-object stored in a Zope folder through a python script using open(), receiving a standard file object, that can be passed to functions provided by standard modules (such as csv) ? f=open(self.index_html), does not work, because open takes only a string as argument. Is there a ZOPE function returning a standard file handler ? (Could not find one in the API docu, but this may be because I am new.) Or how to process a file stored in Zope through a python script ? (Ideally, I would like users to be able to upload files, have them processed and download them again. This seems to be possible with LocalFS, but is it possible from within ZOPE?)