Undefined module
The undefined module provides a Python implementation of the JavaScript undefined value, which can be used in scenarios where a placeholder for “no value” is needed. This module introduces the UndefinedClass and its singleton instance Undefined, which mimics the behavior of undefined in JavaScript. The UndefinedClass is designed to ensure that there is only one instance of Undefined, making it functionally similar to None in Python but with distinct behavior. This class provides several special methods to ensure that Undefined interacts gracefully with Python’s object model, including comparison operations, string representation, and attribute access.