What version of python is used in codecademy tutorials?

I’m a former C and assembly coder who hasn’t written any code in years. I am about half way through the python tutorials, and decided to download python 3.6.2 and IDLE, and immediately found some small syntactic differences between codecademy python and python 3.6.2 as seen in IDLE.
What version of python does codecademy use?


codecademy uses 2.7 version.

To see the version use the following lines of code

import sys
print (sys.version) # need parenthesis in python 3