[Python-Dev] Integrate lxml into the stdlib?

["Martin v. Löwis"]

> I see. I didn't realize you were talking about adding your own files
> to these directories. I have no idea; the best way to find out is to
> experiment. I could see the default policy of Windows installers go
> either way.

An upgrade installation removes all old files it installed (the old
MSI is still present to know what these files are), then installs
new files.

Microsoft intended version resources to be used in the upgrade, so
the upgrade would only have to replace the files that got a new
version (rather than having to do uninstall-then-install).
Unfortunately, that is incapable of upgrading .py files. So Microsoft
added md5 (I think) hashes that can be used to detect files that
don't need upgrade. I tested it, and it was *very* slow, so I reverted
to the current procedure.

In any case, any additional files present will remain untouched.
They will also remain on uninstallation - so uninstallation might not
be able to remove all folders that installation originally created.

Regards,
Martin