Python launching problems OS X
You need to install ipython in addition to python:

$ port search ipython

py-ipython @0.13.2 (python)
An enhanced Interactive Python shell


With

$ sudo port select --set ipython ipython24


you can then select the version you want.

It ill be installed in

$ type ipython
ipython is /opt/local/bin/ipython


Check that your PATH begins with /opt/local/bin and not with opt/local/bin/ (notice the beginning /)