Installing Python 3.5.2 and ActiveState Tcl/Tk

When you run idle, by default, it is /usr/bin/idle which is installed by OS X (El Capitan) as the Python 2.7.10 distribution. It was compiled to look for the ActiveState Tcl v8.5.9 that Apple continues to ship.

When you installed Python 3.5.2, and I hope you did not install it over the existing OS X Python, it was a precompiled binary distribution that may not have been compiled to know about anything more than the available Tcl/Tk Frameworks that were part of OS X at the time. Even if you ran idle3 from within that Python 3.5.2 distribution, you may see no change in Tcl/Tk support.

When one installs Python from a package manager such as Homebrew, or alternatively, builds the source code themselves, there are build parameters (e.g. --with-tcl-tk) that tell the Python 3.5.2 source code to look for the Tcl/Tk Frameworks, and to use the ActiveState 8.6.4+ libraries if they are found. As idle3 is compiled at that time too, it knows to use the latest available Tcl/Tk Frameworks. This is the case with my idle3.

If you plan to build your own Python 3.5.2, you will need the latest command line tools for (OS X El Capitan), and I would encourage you to put the distribution into the /usr/local tree. I patched, and still use pythonbrew for multiple Python distribution juggling, as I have v2.7.12, and 3.5.2 installed. Both of these Python distributions let me build against ActiveState Tcl/Tk libraries.

I just sat down and looked inside the Python 3.5.2 package installer. It deliberately does not step on the default OS X Python installation, when taking the installer defaults. Python 3.5.2 installs its Python.framework in /Library/Frameworks, and command-line binary tools into the /usr/local tree. Therefore, you are ok — providing you did not alter the default install destination.

It is unclear if the Python 3.5.2 installation provides you with a script to switch between Python 3.5.2 and OS X versions of Python. If you reference Python as /usr/local/bin/python, and idle as /usr/local/bin/idle, you should get the 3.5.2 versions of these applications. You may need to set/unset the $PYTHONPATH environment variable to the null string to access the default System Python, or the following to access Python 3.5.2:

/Library/Frameworks/Python.framework/Version/3.5/lib

Well, you know what they say about something being true if it is written on the Internet.... 😉

The following idle and idle3 screen captures tell the story:

You see version 8.6.4 for idle3, because that was the ActiveState Tcl/Tk Frameworks that were installed when I compiled the Python 3.5.2 source with appropriate flag to tell it to use them.

I have read that if you install the ActiveState Tcl/Tk 8.5.18.0 Frameworks after you install Python 3.5.2, that it won't find them, but if you uninstall Python 3.5.2, and then reinstall it, then idle3 will find that latest ActiveState Tcl/Tk Frameworks. You might give that a try.

Here is some code that automatically works for Python 2.7.10, 2.7.12, and 3.5.2:

If there is no obvious uninstaller in the Applications : Python 3.5 folder, then this link offers the following comment that I have highlighted.

If you just simply reinstall Python 3.5, it may now become aware of the more recent Tcl/Tk Frameworks.