About a year ago I wrote about our decision to restrict what languages we use to develop internal tools and mentioned that one of the languages we picked was Python. At the time, I mostly meant Python 2 (although we already had one Python 3 program even then, which I sort of had qualms about). Since I now believe in using Python 3 for new code, I decided that the right thing for us to do was explicitly consider the issue and reach a decision, rather than just tacitly winding up in some state.

Our decision is perhaps unsurprising; my co-workers are entirely willing to go along with a slow migration to Python 3. We've now actively decided that new or significantly revised tools written in Python will be written in Python 3 or ported to it (barring some important reason not to do so, for example if the new code needs to still run on our important OmniOS machines). Python 3 is the more future proof choice, and all of the machines where we're going to run Python in the future have a recent enough version of Python 3.

That this came up now is not happenstance or coincidence. We have a suite of local ZFS cover programs and our own ZFS spares handling system, which are all primarily written in Python 2. With a significantly different fileserver setup on the horizon, I've recently started work on 'porting' these programs over to our new fileserver environment (where, for example, we won't have iSCSI backends). This work involves significant revisions and an entirely new set of code to do things like derive disk mapping information under Linux on our new hardware. When I started writing this new code, I asked myself whether this new code in this new environment should still be Python 2 code or whether we should take the opportunity to move it to Python 3 while I was doing major work anyway. I now have an answer; this code is going to be Python 3 code.

(We have Python 3 code already in production, but that code is not critical in the way that our ZFS status monitoring and spares system will be.)

Existing Python 2 code that's working perfectly fine will mostly or entirely remain that way, because we have much more important things to do right now (and generally, all the time). We'll have to deal with it someday (some of it is already ten years old and will probably run for at least another ten), but it can wait.

(A chunk of this code is our password propagation system, but there's an outside chance that we'll wind up using LDAP in the future and so won't need anything like the current programs.)

As a side note, moving our spares system over to a new environment has been an interesting experience, partly because getting it running initially was a pretty easy thing. But that's another entry.