This is makeindex, version 2.15 [TeX Live 2019] (kpathsea + Thai support).
Scanning style file ./python.ist.......done (7 attributes redefined, 0 ignored).
Scanning input file energysim.idx...done (0 entries accepted, 0 rejected).
Nothing written in energysim.ind.
Transcript written in energysim.ilg.
