Customizing an aggregation function

Pandas provides a number of the most common aggregation functions for you to use with the groupby object. At some point, you will need to write your own customized user-defined functions that don't exist in pandas or NumPy.

Getting ready

In this recipe, we use the college dataset to calculate the mean and standard deviation of the undergraduate student population per state. We then use this information to find the maximum number of standard deviations from the mean that any single population value is per state.

How to do it...

...