If you are relying on the value of distutils.sysconfig.get_python_lib() as you shown in your system, you probably don't want to. That directory (dist-packages) should be for Debian provided packages only, so moving to sysconfig.get_path() would be a good thing, as it has the correct value for user installed packages on your system.

But anyway, there have been introduced mechanisms that should allow distros to deal with these issues. The goal is to make it so that distros can officially customize such details and not have to rely on heavy patching.