How Do Python Programs Use Inheritance? A Replication Study

In this work we present an empirical study on the use of inheritance in a curated corpus of Python systems. Replicating a study preformed on Java, we analyzed a collection of 51 software systems written in Python, and investigated how inheritance is effectively used by Python developers in practice through a convenient set of inheritance metrics. Our results suggest that on average fewer classes inherit from other classes than in Java, but more classes are inherited from. We also see a sort of symmetry relating the number of ancestors and the number of descendants in each system.