Suggestions for dictionary section.

So the idea as I understand it is to cover the entire dictionary section in ten minutes (at least, for instructor training).  Your section is a good overview. In my version, I cleaned it up and shortened it a bit, mainly combining code snippets to try to communicate only one idea at a time.

I suggest excluding the output from the final version as well (Cell→All Output→Clear).  (It occurs to me that a really useful IPython feature would be the ability to hide or selectively reveal cells based on prior input, but that's a separate issue.)

Another approach you may try in the future is to construct a real-world example first, demonstrate it, and then dissect it to illustrate the principle.  (induction)

One thing I like about SWC is I _always_ learn something.  From this, I picked up using 'in' with dictionaries, and that 'get' returns 'None' rather than raising a 'KeyError'—that could be a useful insight since I _hate_ 'try'/'catch'.