Your system is not using the "Universe" repositories. You need to enable the Universe repositories to get
This answer here will explain how to enable those repositories graphically. Once you've enabled them and updated your system with apt-get, you should be able to find that package.
If you are on a command-line-only setup, then I will give you a set of commands to run here, courtesy of bodhi.zazen's answer here.
/etc/apt/sources.list with any editor with superuser powers (for command line, I recommend
sudo nano /etc/apt/sources.list, for graphical,
gksu gedit /etc/apt/sources.list).
(2) Modify your
sources.list file to look similar to this:
###### Ubuntu Main Repos
deb http://us.archive.ubuntu.com/ubuntu/ precise main universe
deb-src http://us.archive.ubuntu.com/ubuntu/ precise main universe
###### Ubuntu Update Repos
deb http://us.archive.ubuntu.com/ubuntu/ precise-security main universe
deb http://us.archive.ubuntu.com/ubuntu/ precise-updates main universe
While this does not put the "Multiverse" repositories in (non-free software), you do not necessarily need Multiverse (if you want it, add "multiverse" to the end of each of the deb lines above.) For whatever archive is there in your current sources.list, use that one instead of the us archives, I'm in the US so I have that in this.
sudo apt-get update to update the repository information
sudo apt-get install python-gasp should now work.