Reinteract - Trac: "Reinteract is a system for interactive experimentation with Python. Reinteract worksheets contain Python code combined with the results of that code, formatted as text or graphical plots. Unlike a traditional shell, you can go back and edit previously entered statements, and the results will update. Among other things, Reinteract is suitable for experimentation with the Python language and for data analysis using the NumPy and SciPy packages."