OSX comes with python. It is likely that the version of python on your path is the out of box version. If you use
which python
you should get the directory location of the python you are calling and you can see if it is the macports or OSX version. The OSX Python on my 10.8 mac is in /Library/Frameworks/Python.framework .
Using Ned Deily's comment below you can find the location of the python you want to use from the terminal. Then you can add a line to your ~./bash_profile to set the PYTHONPATH to the version you want to use like this.
export PYTHONPATH=$PYTHONPATH:/path/to/your/python
Then you must reopen the terminal or source the .bash_profile.
source .bash_profile
Then use the which command again to make sure you have the version you want.