I don't regularly use either language, but I prefer to use Ruby for this: https://robm.me.uk/2013/11/ruby-enp/

Example from that article

    $ echo "foo\nbar\nbaz" | ruby -ne 'BEGIN { i = 1 }; puts "#{i} #{$_}"; i += 1'

output

    1 foo
    2 bar
    3 baz