How to find Windows "Application data" directory??

[Paul Rubin]

I'm writing a Windows program that needs to store some user files.

The logical place to store them is in "Application Data", right?

Is there a good way to find the correct location of that directory,
preferably without any C extensions?  It's ok if the directory is
found at installation time rather than runtime, and bdist_wininst does
have a way to find it from a post-installation script.  The trouble is
that the post-installation script doesn't seem to have an obvious way
to communicate the info to the application for later use!

Any suggestions?

Thanks.