I also recommend `pypyp` python package. You can pipe to python like,

  $ seq 1 10 | pyp "sum(map(int, lines))" 

55

or along with `jq` and `pup` (html parser)

  $ curl https://public-api.wordpress.com/rest/v1.1/sites/username.wordpress.com/posts | jq -r ".posts.content" | pyp "html.unescape(x)" | pup a attr{href}