[Distutils] SetupTools: In Situ Upgrading

Once a script has started, is it possible to forcibly ignore the version of a package listed in easy-install.pth and tell pkg_resources to require a newer version that is available on the sys.path? The script actually installs the newer version using easy_install, but now I want the script to use the newer available version (and forget about the older version). Thanks for any hints, Alex By the way, it appears to me that in the EasyInstall documentation (http://peak.telecommunity.com/DevCenter/EasyInstall) the option --upgrade is elsewhere referred to as --update, but maybe it is my misunderstanding.