the accepted keys should be integers and slice objects. Note that the
special interpretation of negative indexes (if the class wishes to emulate a
:term:`sequence` type) is up to the :meth:`__getitem__` method. If *key* is
- of an inappropriate type, :exc:`TypeError` may be raised; if of a value
+ of an inappropriate type, :exc:`TypeError` may be raised; if *key* is a value
outside the set of indexes for the sequence (after any special
interpretation of negative values), :exc:`IndexError` should be raised. For
:term:`mapping` types, if *key* is missing (not in the container),