[nacs]

Output from my systems right now:

"Ubuntu 15.10" - Python 2.7.10

"Ubuntu 14.04.4 LTS" - Python 2.7.6

Not sure where you're getting the "by default 3.5" from.

[mixmastamyk]

    ＞ python3 --version

Or: http://packages.ubuntu.com/xenial/python3

[johnny22]

the python executable will probably be python 2 for quite some time to come. type python3 --version