csvkit and miller are both extraordinarily slow try xsv (https://github.com/BurntSushi/xsv https://github.com/BurntSushi/xsv) or zsv (https://github.com/liquid

csvkit and miller are both extraordinarily slow try xsv (https://github.com/BurntSushi/xsv https://github.com/BurntSushi/xsv) or zsv (https://github.com/liquidaty/zsv https://github.com/liquidaty/zsv) instead (the latter of which I'm an author of)