3.3.5 Additional methods for emulation of sequence types
The following methods can be defined to further emulate sequence
objects. Immutable sequences methods should only define
__getslice__(); mutable sequences, should define all three
three methods.
-
- __getslice__(self, i, j)]
Called to implement evaluation of self[i:j]. The returned
object should be of the same type as self. Note that missing
i or j in the slice expression are replaced by zero or
sys.maxint, respectively, and no further transformations on the
indices is performed. The interpretation of negative indices and
indices larger than the length of the sequence is up to the method.
-
- __setslice__(self, i, j, sequence)]
Called to implement assignment to self[i:j]. Same notes for
i and j as for __getslice__().
-
- __delslice__(self, i, j)]
Called to implement deletion of self[i:j]. Same notes for
i and j as for __getslice__().
Notice that these methods are only invoked when a single slice with a
single colon is used. For slice operations involving extended slice
notation, __getitem__(), __setitem__()
or__delitem__() is called.