differences in python 2 and python 3

map function, python 2 extending with None to longest, python 3 stop at the shortest. point of interest:

itertools.zip_longest(*iterables, fillvalue=None)

(python 3),

itertools.izip_longest(*iterables[, fillvalue])

(python 2.6+)

integer division, if you want python 2 behavior in python 3, using // instead.

ref: Supporting Python 3, Language differences and workarounds