python __slots__
PySide6.QtCore.Slot - Qt for Python
PySide6 is the official Python module from the Qt for Python project, which provides access to the complete Qt 6.0+ framework.
Using __slots__ to Store Object Data in Python - Stack Abuse
We'll also discuss the tradeoffs for using __slots__, and look at their performance when compared to typical classes that store their instance attributes with dictionaries.
Slots in Python
It also prevents the creation of any variables that aren't declared in __slots__.