.. data:: NotImplemented
- Special value which can be returned by the "rich comparison" special methods
- (:meth:`__eq__`, :meth:`__lt__`, and friends), to indicate that the comparison
- is not implemented with respect to the other type.
+ Special value which should be returned by the special methods
+ (:meth:`__eq__`, :meth:`__lt__`, :meth:`__add__`, etc.) to indicate
+ that the operation is not implemented with respect to the other type.
.. data:: Ellipsis