data formats: comments from 2021

[rkdarst]

• I used !head to view data files. This didn't work on Windows, so we need a pure Python command to do the equivalent of that, e.g. print(open('dataset.csv').readlines()[:3]).
• Show demo of the lines?
• Can we make some sort of simple exercise to do? Perhaps, if nothing else, have people try to save as csv and load again (at the beginning), and then go on to do the rest of the discussion and show the solution?