This is makeindex, version 2.15 [TeX Live 2016] (kpathsea + Thai support). Scanning style file ./python.ist......done (6 attributes redefined, 0 ignored). Scanning input file sound.idx....done (389 entries accepted, 0 rejected). Sorting entries......done (3548 comparisons). Generating output file sound.ind....done (413 lines written, 0 warnings). Output written in sound.ind. Transcript written in sound.ilg.