Brian Granger introduces the IPython Notebook, an open-source, web-based interactive computing environment for Python and other languages. By enabling the data scientist to build documents that combine code, text, formulas, visualizations, images and video the Notebook creates a foundation for data science that is interactive, repeatable, documented and sharable.
Here is the source code:
https://gist.github.com/3837783
And the rendered notebook:
nbviewer.ipython.org/3837783/TwitterNetworkX.ipynb
Here is more info about IPython: ipython.org/