>reads the CSVs from the .zip file Neat! I can't find anything in Clojure that d...

>reads the CSVs from the .zip file

Neat! I can't find anything in Clojure that does that, so I guess I'd have to use java.util.zip via Clojure ineterop. But making records and doing queries is easy:

> generate classes at runtime using the headers in each CSV

In Clojure:

    (ns gtfs.core
       (:require [clojure.data.csv :as csv]))
    
    (defn load-records [f]
      (let [csv-data (csv/read-csv (slurp f))]
        (map zipmap
             (->> (first csv-data) ;; First row is the header
                  (map keyword)
                  repeat)
             (rest csv-data))))
    
    (def agency-maps (load-records "data/agency.txt"))
    (def routes-maps (load-records "data/routes.txt"))
    ;; etc.
    
    (count routes-maps) ;; 30
    (first routes-maps)
    ;; {: route_id "1-100",
    ;;  :route_short_name "1",
    ;;  :route_long_name "Ligne 1",
    ;;  :route_desc "",
    ;;  :route_type "3",
    ;;  :route_url "",
    ;;  :route_color "#B22E75"}

> defines a 'select' function to make queries easy to write

    ;; Query for long_name and route_color 
    (def route_ln_color (map #(select-keys % [:route_long_name :route_color]) routes-maps))
    
    (take 2 route_ln_color)
    ;; ({:route_long_name "Ligne 1", :route_color "#B22E75"}
    ;; {:route_long_name "Ligne 2", :route_color "#B22E75"})