__dict__ and __slots__

The special attribute __slots__ allows you to explicitly state which instance attributes you expect your object instances to have, with the expected results:

1. faster attribute access.
2. space savings in memory.

The space savings is from

1. Storing value references in slots instead of __dict__.
2. Denying __dict__ and __weakref__ creation if parent classes deny them and you declare __slots__.

Resources

• https://towardsdatascience.com/understand-slots-in-python-e3081ef5196d
• https://stackoverflow.com/questions/472000/usage-of-slots