[mod_python] Memory error

I spent some time to write an input filter hoping  that an input filter will
help me upload large files without memory errors.
But it does NOT help.
When I checked Apache error log today I saw:
MemoryError, referer: http://127.0.0.1/mod/mptest.py?17644

( mptest.py is handler I use for uploading .)


 I use
Apache 2.2.4
Mod_python 3.3.0.b
Python 2.3.5


Input filter looks like this

def inputfilter(filter):
	if filter.req.method != 'POST':
		filter.pass_on()
		return
	f=open('uploadedfile','ab')
	
	s = filter.read()
	while s:
		f.write(s)
		f.flush()
		filter.write(s)
		filter.flush()
		s = filter.read()
	if s is None:
		filter.close()
		f.close()

Can anyone help? Will input filter really help or not?
Does anyone have any experience with uploading large files( 100 MB and higher)?
Thank you help
Lad.