Python Machine Learning Blueprints - Second Edition

groupby

Let's now look at an operation that is highly useful, but often difficult for new pandas users to get their heads around: the .groupby() function. We'll walk through a number of examples step by step in order to illustrate the most important functionality.

The groupby operation does exactly what it says: it groups data based on some class or classes you choose. Let's take a look at a simple example using our iris dataset. We'll go back and reimport our original iris dataset, and run our first groupby operation:

Here, data for each species is partitioned and the mean for each feature is provided. Let's take it a step further now and ...