Not everyone has python installed in /usr/bin (in particular, on FreeBSD/NetBSD/etc it would likely be in /usr/local/bin -- and in my own dogfood it could be anywhere.) So, this change makes the hashbang lines use the python found on the search path, using /usr/bin/env. I don't know if this is considered "best practice" exactly, but it's fairly widespread and in my experience it's a pretty good practice.
Not everyone has
pythoninstalled in/usr/bin(in particular, on FreeBSD/NetBSD/etc it would likely be in/usr/local/bin-- and in my own dogfood it could be anywhere.) So, this change makes the hashbang lines use thepythonfound on the search path, using/usr/bin/env. I don't know if this is considered "best practice" exactly, but it's fairly widespread and in my experience it's a pretty good practice.