[Zope] Opening a ZOPE file object ?

[Harm_Kirchhoff at mail.digital.co.jp]

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?)