Writing Small CLI Programs in Common Lisp / Steve Losh

What I love about his approach is that he first thinks about what are his own requirements, before choosing his solution.

Oh, and you should absolutely try Common Lisp. In the 80ies, when I learned programming, Lisp had a reputation of being expensive to get licenses for, extremely resource-hungry and unusable on microcomputers. Today, it is a language that is more powerful than Python and open source implementations like SBCL compile Lisp to native code with roughly about the speed of Java.