Is there an officially updated recommendation indicating which versions of Python should be supported by released modules? Or perhaps a page giving a survey of production usage of various versions? It's difficult to know how much use to make of newish features like context managers, class decorators, etc. when writing a module.
Note that learning which versions of Python are in common usage now is only part of my question; I'd like to find a resource which will provide up-to-date information for future readers of this thread (and myself).
I'm not aware of any single resource keeping an up-to-date summary of production usage of different Python versions, but a good start would probably be to check which Python versions that are distributed with various Linux distributions. Here's a sample for some of the most used server distributions (taken from Distrowatch):
Clearly, Red Hat is the limiting factor here. The latest stable RHEL release ships with Python 2.4, and as there's a fair number of RHEL servers out there, you'll have to target Python 2.4 unless you want Red Hat users to install a newer Python version from source or from third-party RPMs. If you don't mind leaving RHEL behind you could probably go for 2.5 or 2.6 instead.