Is python 2.7 software is best for python language ? If not then why ??

Answer 1

If you are a newbie, don't bother with the 2.X. Go to 3.6 already.

Answer 2

2.7 is going to be unsupported and deprecated soon.

Answer 3

Python 2.7 has a better community, that means that there are more modules for that version of python.
But I program python 3.3, and i think it's better (python 3 has compatibility with all posterior versions)

Choose the one you want :)