Scientific Python moving to Python 3 only.

[Terry Reedy]

https://github.com/numpy/numpy/blob/master/doc/neps/dropping-python2.7-proposal.rst

Numpy people currently plan to stop adding features to their 2.7 branch 
after Dec 31, 2018 and stop adding bug fixes to the last version 
supporting 2.7 a year later, Dec 31, 2019.  It will remain available for 
pip installation, and possible support by other (most likely commercial) 
parties.

http://www.python3statement.org/
About 30 other projects, including other part of the python-science 
stack, have 'pledged' to so something similar.

-- 
Terry Jan Reedy