Python-yql is available from the cheeseship (PyPi) and on launchpad
With setuptools all you need to do is run the following command:
sudo easy_install yql
You can also get a tarball from PyPi with:
wget http://pypi.python.org/packages/source/y/yql/yql-0.2.tar.gz
tar -xzf yql-0.2.tar.gz
cd yql-0.2
python setup.py install
bzr branch lp:python-yql