The [language documentation](https://docs.python.org/3/reference/datamodel.html#invoking-descriptors) states:

> Data descriptors with __set__() and __get__() defined always override a redefinition in an instance dictionary. In contrast, non-data descriptors can be overridden by instances.

This override is not limited to data descriptors defining `__set__()` (and `__get__()`). It is also true for data descriptors defining `__delete__()` (and `__get__()`) and data descriptors defining both `__set__()` and `__delete__()` (and `__get__()`).

In other words, _any_ data descriptors (objects defining either `__set__()` or `__delete__()` or both) defining `__get__()` override an attribute redefinition in an instance dictionary.