While reading the excellent book "Programming Collective Intelligence", I got interested to learn Python again. I did some googling and found that the Python interpreter comes with Mac OS X. I tried typing "python" on the terminal window and sure enough, I got the prompt. Only, my version is 2.5.
I went to the Python website to download the upgrade, installed the upgrade and ... nothing seemed to have happened. When I call the interpreter, I still get version 2.5 (it should have been at least version 3. I did some investigating again and found Python installed at /usr/local/bin. Moreover, I found the two versions installed: python2.5 and python3.1.
Typing "python3" on the prompt got me the updated version!