I'm running Python 2.7 on OS X Snow Leopard. I installed Python using Macports. Then, I installed py27-pyqt4 and py27-pyside, and I can't get them to work.
Python doesn't give errors when I import, but I get the following errors in the terminal when I test either:

pyside-uic : command not found
pyuic4 : command not found
You are still using the default Mac OS Python and not using the new installed one.

Check the python version: python must be 2.7. 
find the new
version (should be inside /usr/local/bin ) 
update your
.bash_profile PATH=/usr/local/bin/:$PATH 
Try again and try to
import PyQt4
pyside-uic/pyuic4: command not found