> I am not sure what you are trying to propose here. The slice object > isn't special, it's just a regular built-in type.
The idea is to have slice objects be generators. You could make a slice like 1:10:2 , and that would make a slice object which could be used as a list index. The list would return a list with the corresponding item for every index in the generator. Then, lists could transparently be used as list indexes, or you could supply your own generator instead of a slice object. > I don't see how introducing new syntax would simplify indexing. It would move the slice logic from the list to the slice object. Now the slice object is just a container, but with this it would be useful. > Why should lists accept a list or a generator as an index? What is the > use case you have in mind? For example, a multiple selection box's selection would be changed into its values by supplying the chosen indexes into a list of values. > > Optionally, the 1:2 syntax would create a slice object outside of list > > index areas. > > Again, I don't see how this could be useful... > > > > >>> list(1:5) > > [1, 2, 3, 4] > > > > >>> list(1:5:2) > > [1, 3] > > > > list(range(1,5,2))? It would only be useful as shorthand for xrange, but its addition capabilities would be useful. > > >>> range(30)[1:5 + 15:17] > > [1, 2, 3, 4, 15, 16] > > > > This is confusing, IMHO, and doesn't provide any advantage over: > > >>> s = list(range(30)) > >>> s[1:5] + s[15:17] > I don't think it's confusing. Also, an advantage would be if the slice object were being automatically generated, this would simplify the code. > If you really needed it, you could define a custom class with a fancy > __getitem__ > > class A: > def __getitem__(self, x): > return x > > >>> A()[1:3,2:5] > (slice(1, 3, None), slice(2, 5, None)) > > P.S. You should consider using the python-ideas > (http://mail.python.org/mailman/listinfo/python-ideas) mailing list, > instead of python-dev for posting suggestions. > > Cheers, > -- Alexandre > _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
