[seiferteric]

Why didn't python just opt to have the python 2 and 3 interpreter in the same binary? It could have detected if a file was python3 with a magic comment or something (overridable with a -2/-3 option), or otherwise assume python2. Or even simpler, have a wrapper script just called 'python' that checks if the file you are calling is python2 or 3 and calls the appropriate binary.

[Zancarius]

"Explicit is better than implicit." is the Python mantra. Although it's not often taken as literally as some would like, I think it's appropriate in this case. After all, magic detection sounds good on the surface, but it's liable to be problematic and bug ridden.

You don't need magical file-specific juju or a wrapper script on most systems these days to select the Python version. Just call python2 or python3 as appropriate; the symlinks usually exist depending on packager, distro, etc. The problem up-thread appears to be with calling the default `python` on $PATH. Sometimes it points to Python 2.x, sometimes it points to Python 3.x. Sometimes it might even change (Gentoo's eselect, IIRC). I don't see the problem being explicit with which version is needed in the script's hashbang. Python 3 isn't exactly new, and I remember when Gentoo and Arch both migrated to versioned symlinks. It wasn't that painful.