As we have already mentioned, descriptors need to be set as class attributes to work. This should not be a problem most of the time, but it does come with some warnings that need to be taken into consideration.
The problem with class attributes is that they are shared across all instances of that class. Descriptors are not an exception here, so if we try to keep data in a descriptor object, keep in mind that all of them will have access to the same value.
Let's see what happens when we incorrectly define a descriptor that keeps the data itself, instead of storing it in each object:
class SharedDataDescriptor: def __init__(self, initial_value): self.value = initial_value def __get__(self, instance, owner): ...
