Property Manager

The `property-manager` package, currently at version 3.0, provides useful property variants for Python programming, extending Python's built-in `property` descriptor. It offers decorators for creating required properties, writable properties, and cached properties, as well as a `PropertyManager` base class with enhanced constructor behavior and `repr()` customization. The library has a stable release cadence, with version 3.0 released in 2020, and is designed to make managing class attributes more robust and flexible.