re IDEs: that's how I work in emacs - python-mode has a binding that shoves the current function or region over to a python-interactive buffer. Simple but effective.
re symbols: I've used enumerator classes when I've needed that kind of thing, but it never reels quite elegant enough. But I *would* generally prefer a class to lisp-style freeform lists, tuples are too "weak" for any structure you're using at a distance...
Do you still have the Python version of Astrologica? I am wondering if you would be willing to put it up for download from your Labs? It sounds like it might be fun to play with.
Much as I like Python, I only use it because there is no environment close to it in a Lisp-like language (i.e., "batteries included").
In my experience, Python forces the use of a common language (phythonic code) to solve a problem, whereas Lisp-like languages encourage the development of a language to attack the problem. Where Python has idioms, Lisp encourages another level of abstraction.
It has to be said that I find it harder to code in Lisp (perhaps because I've never done a very large project in Lisp?) than in Python.