> However, the Clojure REPL story, being a Lisp, just makes the Python interactive introspection experience look pathetic.

Have you ever used ipython? Can you give an example of how it pales in comparison? Typing dir() or help() sounds awful, I hope no full-time Python developers do that.

    import csv
    csv.<tab>

Blammo, tab completed dir().

    csv.reader?

Blammo, docstring, method signature, and more.

    csv.reader??

Blammo, code for the method.