It is not clear to me that that would be correct, though.  Isn't the whole point of __index__ that some types can act as indicies even though they are *not* integers?  Shouldn't it be up to the type to decide if converting them to int is a sensible thing to do?  Maybe that's being silly/pendantic, though.  On the gripping hand, it feels like this is another case of what you have pointed out elsewhere, that it is not clear that we actually have a consistent API here...