[PATCH 1 of 5] pycompat: provide 'ispy3' constant

[Yuya Nishihara]

On Thu, 29 Sep 2016 21:06:09 +0530, Pulkit Goyal wrote:
> Is loading the whole pycompat module just to have this constant is not
> an overkill, I mean its not necessary and loading a module will have
> effects on runtime I guess.

pycompat.py should be loaded at very early stage because one of the core
module, util.py, depends on it. So importing pycompat would be instant.