afaik, the latest portato doesnt use that package anymore, so just unmerge it and get the latest portato after you've cleared the python updater
All the info you need to resolve these issues is in the guide i posted last nighthttp://wiki.sabayonlinux.org/index.php?title=HOWTO:_The_Complete_Portage_Guide
The gentoo handbook is also an invaluable resource http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=2
, it may take some time to get through all this(dont be too daunted), you will learn a lot about the portage system. Pay close attention to the errors, it usually tells you exactly what to do, just read it and refer back to the handbook.
e.g. your latest error was about a masked package, so go to the appropriate section of the handbook and it will tell you exactly7 how to resolve the issue. If you are completely stuck you are always welcome to come to the sabayon irc room (chat link on the main site), there are a lot of very knowledgeable and helpful people in there. Just gotta be patient in waiting for a response, depending on the time of day.
EDIT: in fact just emerge the latest version of portato and that should clear that dependency issue you're currently having, then re-run python-updater