The library that I first used which got me stuck to Python was Tkinter. It was a welcome relief from building GUIs using GTK in C. The documentation which I used was from effbot (which seems to be offline now) http://web.archive.org/web/20180802131839/http://effbot.org/.... That led me to making Python my "primary language" when it still wasn't very popular and shaped my career.

I think it's hard, if not impossible, to overestimate how many lives Mr. Lundh's work has touched and improved over the course of his career. RIP.