Stan W writes (NB. edited for brevity):

Over the last couple of days I have started using your great book with my two sons (13 and 15 years old). I’m reaching out to you with the following question because I have noticed other people asking about the same issue online, with at least one mentioning your book, so I think you posting the question and answer to your blog might help other people in addition *to me and my sons.

We are using Mac OSX and have installed Python 3.3.3 from python.org, and are getting this message when opening IDLE:

“WARNING: The version of Tcl/Tk (8.5.9) in use may be unstable. Visit http://www.python.org/download/mac/tcltk/ for current information.”\

I have installed “Mac OS X 64-bit/32-bit Installer (3.3.3) for Mac OS X 10.6 and later” (file: python-3.3.3-macosx10.6.dmg) and installed the “ActiveTcl 8.6.1 for Mac OS X (10.5+, x86_64/x86)” (file: ActiveTcl8.6.1.1.297588-macosx10.5-i386-x86_64-threaded), but IDLE keeps showing the same error message.

Thank you very much for any help you can provide!*

I’m not convinced ActiveTcl 8.6.1 is the right version to install - I suspect rather than installing the latest and greatest, you should be using version 8.5.15.0. Python (and thus IDLE) will probably be using the latest 8.5 version of Tcl/Tk (i.e. 8.5.x) — you’re installing a completely different version (8.6), which it’s not looking for at all. Hence even though you think you’ve re-installed, you’ll still be getting the same error message.

Hope that helps.