Creating new columns in sublevel of multindex pandas columns
问题 I have a multindex column. Higher level is some humans, sublevel is some measures. I would like to create some new columns which are derivatives of measures (eg. rolling mean). I was hoping I could use some index slicing to achieve this, but alas now. I've found some similar-ish questions here in the past, but they were old questions, and I suspect there are more modern, pythonic solutions. Below is toy example where I demonstrate what I'm trying to do for one column (which works) but shows