https://www.jetbrains.com/research/python-developers-survey-2017/ “Which version of Python do you use the most?” 2014 80% 2.x, 20% 3.x 2016 60% 2.x, 40% 3.x 2017 25% 2.x, 75% 3.x
This is a bigger jump than I anticipated. -- Terry Jan Reedy -- https://mail.python.org/mailman/listinfo/python-list
