[Python-Dev] slice subscripts for sequences and mappings

[Antoine Pitrou]

Hi,

> I'd expect slice subscripts to be part of the sequence interface, and
> yet they are not. In fact, they are part of the mapping interface. For
> example, the list object has its slice get/set methods assigned to a
> PyMappingMethods struct. So does a bytes object, and pretty much every
> other object that wants to support subscripts.

It comes from:
http://hg.python.org/cpython/rev/245224d1b8c9
http://bugs.python.org/issue400998

Written by Michael Hudson and reviewed by Guido.
I wonder why this patch chose to add mapping protocol support to tuples
and lists, rather than add a tp_ slot for extended slicing.

Regards

Antoine.