Python and Tk on MacOSX

The standard binary installation of Python on MacOSX does not include Tkinter. You can use Tkinter on MacOSX, but you have to download TclTkAqua yourself and build Python from source.

Here is a recipe that works for me on MacOSX 10.2 with Python 2.3.3:

Download and install TclTkAqua from http://www.maths.mq.edu.au/~steffen/tcltk/TclTkAqua/ (I used the 8.4.4 Batteries Included installer but I only installed Tcl and Tk. The plain-vanilla TclTkAqua installer would probably be fine as well.)
Download and uncompress the source distribution of Python, the one listed as "for Unix or OS X compile".
If you are building under MacOSX 10.2, you have to make a change to /Python-2.3.3/Mac/OSX/Makefile. Uncomment line 14 (remove the #) and comment line 16 (add a #).
In Terminal cd to the Python directory and enter the commands

./configure --enable-framework
make
sudo make frameworkinstall

This will build /Library/Frameworks/Python.framework and /Applications/MacPython. At this point I can

run python and pythonw from Terminal
run PythonIDE (the Mac IDE) by double-clicking the launcher in the MacPython folder
run IDLE by double-clicking the launcher in the MacPython folder

(The IDLE launcher didn't work for me with Python 2.3.1. But the command 'pythonw idle' where idle is in the current directory, worked for me to launch IDLE. Or just look at the idle file and type the two lines yourself.)
Note that to run ANY Python GUI on MacOSX, you have to run with pythonw or PythonLauncher.