What I find interesting is how Peter builds bottom up solutions using low level utilities. This is how I have always coded in Lisp languages, but when I use Python I tend to write little monoliths. Since I now have to use Python for most of my work (deep learning), I should change the way I use Python. Reading his code is educational.

Peter and I each wrote a Common Lisp book about 25 years ago and a few years after that we had lunch and I was into Lisp and he had transitioned to the practicality of Python. I have a serious bias in favor of Lisp languages that probably has not served me very well. I once had a short talk with Alexis Ohanian about how he and his partner Steve had to convert Reddit from Common Lisp to Python, I think that he described the situation as something like “the Lisp version kept falling down.”