I've compiled conda packages for kwant (and it's dependencies) for Python 2.7, 3.4, and 3.5 for both Linux and OS X.

They can be found on anaconda.org/basnijholt/kwant.

The advantage of having these packages is that they are already compiled. Conda is a packaging tool and installer that aims to do more than what pip does; handle library dependencies outside of the Python packages as well as the Python packages themselves. 

In this way you won't have to install any other dependencies, so when you have a fresh Ubuntu install, all you need to do is install miniconda or Anaconda and run: 

That's it! Let me know if you run into any trouble.

Best, Bas Nijholt