(I answer here because I'm still not at easy on python-dev) It looks like an interesting feature. I think most LOGOs allows something similar (or better, with a cleaner syntax). The shells of many versions of this language keep a "pool" of functions defined with "to" into a kind of database, so you can call them and edit them one at a time (this is a small block from Wikipedia; note that LOGO allows to do more than just turtle graphic):
to spiral :size if :size > 30 [stop] ; a condition stop fd :size rt 15 ; many lines of action spiral :size *1.02 ; the tailend recursive call end In Mathematica you can edit "cells" of the interactive document, you can press enter to go to the next line inside the same cell, and then you press SHIFT+enter to "compile" and execute the text in the cell (usually going to the cell that follows the output one). Some similar "improvements" of the CPython shell can be useful... but I think you first need to look in many places (Smalltalk, LOGO, Mathematica, Mathcad, etc.) to find the best ideas to copy from. Bear hugs, Bearophile -- http://mail.python.org/mailman/listinfo/python-list
