Greg Landrum posted the following to the RDKit users and since a couple of the Jupyter Notebooks I've published make extensive use of RDKit I thought I'd flag it.

As many of you are no doubt aware, the Python community plans to discontinue support for Python 2 in 2020. A growing number of projects in the Scientific Python stack are making the same transition and have made that explicit here: http://www.python3statement.org/

I will be adding the RDKit to this list. The RDKit will switch to support only Python 3 by 2020. At some point between now and then - likely during the 2018.09 release cycle - we will create a maintenance branch for Python 2 that will continue to get bug fixes but will no longer have new Python features added. This branch will be maintained, and we will keep doing Python 2 builds, until 2020 when official Python 2 support ends.

Additionally, starting during the 2018.03 release cycle we will accept contributions for new features that are not compatible with Python 2 as long as those features are implemented in such a way that they don't break existing Python 2 code (more on this later). This will allow members of the RDKit community who have made the switch to Python 3 to start making use of the new features of the language in their RDKit contributions.

If you have not made the switch yet to Python 3: please read the web page I link to above and take a look at the list of projects that have committed to transition. The switch from Python 2 to Python 3 isn't always easy, but it's not getting any easier with time and you have a few years to complete it. There are a lot of online resources available to help.

Best Regards, -greg

The list of projects that will be making the transition so far includes; IPython, Jupyter notebook, pandas, Matplotlib SymPy, Astropy, Software Carpentry, SunPy xonsh, scikit-bio, PyStan, Axelrod osBrain, PyMeasure, rpy2, PyMC3, FEniCS, An Introduction to Applied Bioinformatics, music21, QIIME, Altair, gala, cual-id, CIS