On Tue, 01 Mar 2011 16:26:05 -0500, Eric Smith
On 3/1/2011 4:19 PM, Kerrick Staley wrote:
Hello, There is a need for the default Python2 install to place a symlink at /usr/bin/python2 that points to /usr/bin/python, or for the documentation to recommend that packagers ensure that python2 is defined. Also, all documentation should be changed to recommend that "#!/usr/bin/env python2" be used as the shebang for Python 2 scripts. This is needed because some distributions (Arch Linux, in particular), point /usr/bin/python to /usr/bin/python3, while others (including Slackware, Debian, and the BSDs, probably more) do not even define the python2 command. This means that a script has no way of achieving cross-platform compatibility. The point at which many distributions begin to alias /usr/bin/python to /usr/bin/python3 is due soon, and for the next couple of years, it would be best to use a python2 or python3 shebang in all scripts, making no assumptions about plain python, which should only be invoked interactively. This email from about 3 years ago seems relevant: : http://mail.python.org/pipermail/python-3000/2008-March/012421.html Again, this issue needs to be addressed by the Python developers themselves so that different *nix distributions will handle it consistently, allowing Python scripts to continue to be cross-platform.
I believe we agreed at the language summit last year (or maybe even the year before) that "python" would always be python2.x, and "python3" would be python3.x.
And by "always" we indeed meant forever. To do otherwise would break scripts even many, many years from now.
It sounds like the distributions aren't going to cooperate with us. Arch has already switched. Gentoo will allow the user to switch /usr/bin/python to point to python3, and I suspect this will become the default at some point. I'm not sad about that, myself. --David