sudo apt-get install python-libtiff
at a terminal.
Update: This does not appear to work in Ubuntu 14.04. It results in installation of version 0.3.0, which I believe has been replaced by 0.4.0. You can download the newest version at https://pypi.python.org/pypi/libtiff/ then unpack it, cd to the directory, and run
sudo python setup.py install
For some reason you will need to move out of the downloaded directory in order to actually test it, though. Open a python interactive prompt and make sure that you can import it:
from libtiff import TIFF
Below is a snippet of some code that I've been using to open a 2-channel (2-color) image stack and arrange the dimensions in a way that I find intuitive (x,y,z,color).