So for so good on the first two chapters of Phillip Janert’s Data Analysis with Open Source Tools. Actually better than good, it’s been great. A little statistics, a little graphics, a little math, and a little programming. All starting from an expectation that the reader is somewhat experienced and with a matching serious tone. Kernel density estimates were actually new to me. A number of O’Reilly books start off a bit breezy, but not this one. Well worth the money so far.