I'm still running a twelve year old Python program

April 25, 2015

I've been thinking for a while about the interesting and perhaps somewhat remarkable fact that I'm still running a twelve year old Python program (although not as intensely as I used to be). When I say twelve year old, I don't mean that the program was first written twelve years ago and is still running; I mean that the code hasn't been touched since 2004. For bonus points, it uses a compiled module and the source of the module hasn't been changed since 2004 either (although I have periodically rebuilt it, including moving it from 32-bit to 64-bit).

(I was going to say that the tests all still pass, but it turns out that I burned a now-obsolete IP address into one of them. Oops. Other than that, all the tests still pass.)

While the code uses old idioms (it entirely uses the two argument form of raise, for example), none of them are so old and questionable that Python 2 emits deprecation warnings for them. I'm actually a little bit surprised by that; even back in 2004 I was probably writing old fashioned code. Apparently it's still not too old fashioned.

Some of the long life of this old code can be attributed to the fact that Python 2 has been moving slowly. In 2004 I was writing against some version of Python 2.3, and the Python 2 line stopped really changing no later than Python 2.7 in 2010. Really, I doubt anyone was in a mood to deprecate very much in Python 2 after 2007 or so, and maybe earlier (I don't know when serious Python 3 development started; 3.0 was released at the end of 2008).

(With that said, Python 2.6 did deprecate some things, and there were changes in Python 2.4 and 2.5 as well.)

My impression is that this is a reasonably surprising lifespan for an unchanged set of source code, especially in an interpreted language. Even in a compiled language like C, I'd expect to have to update some function prototypes and stuff (never mind a move from 32 bits to 64 bits). While it's certainly been convenient for me in that I haven't had to pay any attention to this program and it just worked and worked even as I upgraded my system, I find myself a little bit sad that Python 2 has moved so slowly that twelve years later my code doesn't even get a single deprecation warning.

(The flip side argument is that my code would get plenty of warnings and explosions if I ran it on Python 3. In this view the language of Python as a whole has definitely moved on and I have just chosen to stay behind in a frozen pocket of oldness that was left for people like me, people who had old code they didn't want to bother touching.)

PS: It turns out that the Github repo is somewhat ahead of the state of the code I have running on my system. Apparently I did some updates when I set up the Github repo without actually updating the installed version. Such are the hazards of having any number of copies of code directories.

Written on 25 April 2015.
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My complicated feelings on abandoning old but good code »

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Last modified: Sat Apr 25 01:15:28 2015
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