Evaluating the Sized type for a Quantity is not working properly.
Lets say I want to evaluate the length of a Quantity x = 1*u.s, if this is only a single value len(x) will raise an exception.

In this case using something like

from collections.abc import Sized
if isinstance(x, Sized):
    print(len(x))

is a nice way to solve this issue. However this will always evaluate to True even if the Quantity only contains a single Value.
This would require to somehow implement the __len__ method more dynamically or delete it if only a single value is contained.
Im not sure if this is possible.