Please add support for `#[deleter]`

[linkmauve]

PyO3 currently implements #[getter], #[setter], but surprisingly not #[deleter], so we can’t implement del object.property despite that being a somewhat common Python operation.

We can workaround this by making the setter accept an Optional[…] and behave as if the property was deleted when set to None, but that’s still missing compared to a prior Python implementation.

Thanks.

[davidhewitt]

Agreed, seems like an oversight in the original implementation. I think probably the workaround you suggest is unhelpful, because it's not possible to distinguish between None being "I want to set this to None" and "I want to delete the attribute".

We might have to be careful about backwards compatibility.