check_skeleton()
Inspect a product and report which parts carry real values.
Usage
check_skeleton(path)A geometry column counts as unfilled when it is entirely zero, which is what writer.build_hdulist() writes for a column the caller omitted. That is a heuristic – a genuinely all-zero backplane would be reported as unfilled – but for the intended use (did my arrays land where I meant them to?) it is the useful answer.