Python package to read .7z archives?

[Hallvard B Furuseth]

Is there an equivalent of zipfile.py for .7z archives?
I have one which extracts an archive member by running 7z e -so,
but that's a *slow* way to read one file at a time.

Google found me some python interfaces to lzma, but apparently they
only handle single compressed files, not .7z archives.

(Actually another archive format would be fine if it is competitive.
I'm just looking to compress my .zips better.  I need a Python module
to extract members reasonably fast, but slow compression would be OK.)

-- 
Hallvard