I believe this feature was introduced in Python 3.6. This implementation may be 3.6 <

Edit: Just checked the site and see it uses PyPy which states -- on their site -- the python version is 3.5.3

Or you know, just import sys and print sys.version instead of reverse-engineering it from the syntactic features introduced over time.

I can't do:

a, *b = range(3)

which should be 3.5 i think.

Other comments in this thread point to the implementation likely being Python 2.x.