[Python-3000] dict view operations

["Martin v. Löwis"]

Guido van Rossum schrieb:
> On 9/4/07, "Martin v. Löwis" <martin at v.loewis.de> wrote:
>>> Oh, and another thing: the items views can contain unhashable values
>> That, of course, could be fixed: if the key-value pairs would only
>> hash by key (ignoring the value), they would remain hashable.
> 
> How would that help? The key/value pairs are ordinary tuples

They would have to stop being that:

class Association(tuple):
  def __hash__(self):
    return hash(self[0])

> What use case are you thinking of that this would address?

It would allow to treat the items view as a proper set (which
it still is).

Regards,
Martin