I’m currently working on a new Plone add-on to manage the upload and distribution of product add-ons / extensions. I develop this add-on from scratch with my experience from other Plone add-ons which I created within a Python 2 Plone environment.
The development of the new add-on is done inside an environment of the latest Plone version (5.2) in combination with Python 3 (3.6 in this case). I started the development using Python 3 because the support for Python 2 stopps in less than five month and I thought it is not usefull to create a new add-on within an nearly outdated Python environment.
You could get the calculation of the Python 2 version retirement at pythonclock.org.
It’s time for projects using Python 2 to think about the migration to Python 3 soon.