You can check out QuakePy from our Subversion repository at https://quake.ethz.ch/svn/quakepy. You need a Subversion client on your machine to do so.
The checkout can be performed using the following commands:
svn checkout https://quake.ethz.ch/svn/quakepy/trunk quakepy
This will create a directory quakepy in your current directory which contains the QuakePy code.
QuakePy needs a couple of other packages to be installed. Please check out ListOfPackages to see which packages are required.
After downloading QuakePy, you need to add the QuakePy directory to your PYTHONPATH, using
for bash, or
setenv PYTHONPATH /my/quakepy/installation:$PYTHONPATH