Why Python’s Boolean Is Actually an Integer Subclass – Explained

1. Introduction

Hello, I’m PiPi. A few days ago a member of a Python community asked a basic question about the Python type system, as shown in the screenshot.

2. Implementation Details

The discussion concluded that the Boolean type in Python is a numeric type. The following code (shown in the image) demonstrates that bool and int share the same underlying type, but the objects True and 1 have different id values, meaning they are distinct objects.

Further screenshots show that bool is a subclass of int. Using the __base__ attribute confirms that the parent class of bool is int.

The article also clarifies the difference between the is operator and the == operator, illustrated by the following diagram.

3. Summary

This article reviews a basic Python type question, provides detailed analysis and code examples, and helps readers understand why Boolean values are considered numeric and how they relate to integers.

References: https://zhuanlan.zhihu.com/p/33907983, https://www.cnblogs.com/greatfish/p/6045088.html, https://mrcuriosity.org/python-string-intern.html.