That was my initial reaction too, however I think the author was listing _all_ of the libraries used by Asciinema, rather than just the ones they had to find ou

That was my initial reaction too, however I think the author was listing _all_ of the libraries used by Asciinema, rather than just the ones they had to find outside of the standard lib. Their point being that Python includes them all, so there's no need to go external.