When Arch Linux switched its /usr/bin/python from python-2.x to python-3.x, it caused a little controversy… There were rumours that it had been decided upstream that /usr/bin/python would always point at a python-2.x install (although what version that should be was unclear). Although these rumours were abundant and so more than likely such a discussion did occur (probably offline at PyCon 2009), this decision was never documented. Also, whether such a decision can formally be made off the main development list is debatable.

Enter PEP 394. Depending on how I am feeling, I call this the “justify Arch’s treatment of python” PEP or the “make Debian include a python2 symlink” PEP. Either way, the basic outcome is:

python2 will refer to some version of Python 2.x

python3 will refer to some version of Python 3.x

python should refer to the same target as python2 but may refer to python3 on some bleeding edge distributions

The PEP is still labeled as a draft, but all discussion is over as far as I can tell and I think it will probably be accepted without much of any further modification. The upshot is, using “ #!/usr/bin/env python2 ” and “ #!/usr/bin/env python3 ” in your code will become the gold standard (unless of course you code can run on both python-2.x and python-3.x). There is still no guarantee what versions of python-2.x or python-3.x you will get, but it is better than nothing…