1. It seems... tempting but ill-advised to make it a "fake" ConfigParser option if in the place where I use it, I'm not actually parsing the file with full ConfigParser semantics. It might work, but then someone tries to get clever with a [DEFAULT] section, or interpolation, or who knows what else, and it breaks mysteriously.
It’s still time to define the file format as RawConfigParser-style, without interpolation.
2. I still have to duplicate in C and Python code the logic for finding the config file in the first place. Or I guess just move it to C and stash the location in sys or somewhere the Python code can get to it later. I'd been hoping to avoid this, but oh well...
*hands a courage cookie* I have to say the proof of concept in pure Python was impressive. Too bad it’s not enough :) Cheers