The script fetches the composer-tag.
The Deezer database has no information about genres.
The tracknumber is written to the tag TRACK.
The total number of discs and the total number of tracks are written to the Tags TRACK and DISCNUMBER after the slash. This is the way it is provided in the ID3v2-standard.
https://id3.org/id3v2.3.0
There are no official tags like TRACKNUMBER, TRACKTOTAL and DISCTOTAL.