ineedpy2: Library to swap to newer python version on a multi-version system.

Find the latest Python 2 version installed on the system and if this program is not running on that version, re-invoke it with that version.

Background

One of the problems of a system administrator is that enterprise Linux distros which ship with, and often require, /usr/bin/python to be a fairly old versions. For example, Python 2.1. Applications can be very difficult to write such that they are happy on Python 2.1 and Python 2.7. Many of these distros include a newer Python, but it has to be invoked as "python2.6", for example.

You can change the "#!" line in the script, but this makes packaging more difficult.

Examples

To make sure you are running on the absolutely latest installed Python 2 on the system:

import sys
print 'Version:', sys.version_info
import ineedpy2
ineedpy2.rerunonlatest()

If run on a system with the default Python version being 2.1, but python 2.6 also installed will display:

Version: (2, 1, 3, 'final', 0)
Version: (2, 6, 5, 'final', 0)

NOTE: Anything run before the "runonlatestpy2" will be run once on the older version and once on the newer version.

You can also request the reinvocation only if the python minor version isn't at least a specific value. In other words, "I know I need at least Python 2.4":

from ineedpy2 import requireminor
requireminor(4)

License

Copyright (c) 2011, Sean Reifschneider jafo@tummy.com, tummy.com, ltd.
Released under the Python Software Foundation License
For more information, see: http://docs.python.org/license.html