How to install Python newt or snack in Mac OS X for byobu
Try,
sudo port install libnewt
After that, you may need to add /opt/local/lib/python2.6/site-packages to PYTHONPATH as follows,
export PYTHONPATH=/opt/local/lib/python2.6/site-packages/
or
setenv PYTHONPATH /opt/local/lib/python2.6/site-packages/