The __getslice__, __setslice__ and __delslice__ methods have been deprecated since Python 2.0. In general, no class should implement these methods.

The only exceptions to this rule are classes that inherit from list and override __getitem__, __setitem__ or __delitem__. Since list implements the slicing methods any class inheriting from list must implement the the slicing methods to ensure correct behavior of __getitem__, __setitem__ and __delitem__. These exceptions to the rule will not be treated as violations.