Please see Python OS X development environment. The best way is to use MacPorts. Download and install MacPorts, then install Python via MacPorts by typing the following commands in the Terminal:
sudo port install python26 python_select sudo port select --set python python26
OR
sudo port install python30 python_select sudo port select --set python python30
Use the first set of commands to install Python 2.6 and the second set to install Python 3.0. Then use:
sudo port install py26-packagename
OR
sudo port install py30-packagename
In the above commands, replace packagename with the name of the package, for example:
sudo port install py26-setuptools
These commands will automatically install the package (and its dependencies) for the given Python version.
For a full list of available packages for Python, type:
port list | grep py26-
OR
port list | grep py30-
Which command you use depends on which version of Python you chose to install.