How to install Python and wxPython offline?
Generally, installing packages offline is well... drama. You can download the .deb files from http://packages.ubuntu.com/raring, but you have to be very careful. You should also download and install all dependencies, which can be tens and even hundreds for some packages. Normally, sudo apt-get install [package_name] does this all for you automatically, but doing it manually is a hell of a job.
That said: Base Python is installed by default on Ubuntu. wxPython is downloadable here, but be sure to first download and install all dependencies.