The best solution I’ve seen is to prefix logging statements with if __debug__: so that they are optimized away by python -O (see this post on StackOverflow). I like it, but it unfortunately requires this statement to be prefixed to every logging statement I don’t want in a production environment. That’s a lot of ugly extra code and it isn’t easy to change which statements it applies to either.

I decided to write a script which automatically parses a Python file and replaces logging statements of a particular level with a pass statement and a commented out copy of the logging code. It can also do the reverse operation. It has some limitations (see the code, or run the script with the --help option), but it should work for most Python files. I used it for the VNS project and it successfully operated on every file in the project. It also improved performance dramatically – the maximum throughput of the VNS simulator increased by 25%! In comparison, running the code with Psyco only garnered a 6% improvement (though pretty substantial for the minimal 13 lines I had to add to take advantage of it).

I think this script is worth using before running your code in a production environment if you are a heavy user of the logging module like I am. You can find the code here (it is hosted on Siafoo, a neat site for sharing code). Here’s the latest version of the code: