Python complaints

Eric Jacobs x at x.x
Sat Nov 27 04:52:32 CET 1999


David Ascher wrote:
> 
> Without dealing with the last paragraph, you can fake it now, with
> something like (barely tested):
> 
> import types
> class XRangeClass:
>     def __getitem__(self, item):
>         if type(item) == types.SliceType:
>             if item.start is None:
>                 start = 0
>             else:
>                 start = item.start
>             if item.step is None:
>                 step = 1
>             else:
>                 step = item.step
>             if item.stop is None:
>                 stop = sys.maxint
>             else:
>                 stop = item.stop
>             return xrange(start, stop, step)
>         elif type(item) == types.IntType:
>             return item
>         else:
>             raise ValueError, "XRanges needs to be sliced with indices or slices"

Actually, they can be sliced with tuples too (try Int[1:2, 4:5]). But you
get the idea. I don't think a change in Python syntax is needed to clean
up range and xrange.

Allowing slice indices to be any objects, and not just integers...
that could be a nice addition. Like in the Enumerator metaclass example:
you could have

    for x in Color[red:blue]: ...

>     def __getslice__(self, start, stop):
>         return self.__getitem__(slice(start, stop, None))
> 
> Int = XRangeClass()




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