M.-A. Lemburg wrote:
Walter Dörwald wrote:
M.-A. Lemburg wrote:
[...]
__str__ and __unicode__ as well as the other hooks were specifically added for the type constructors to use. However, these were added at a time where sub-classing of types was not possible, so it's time now to reconsider whether this functionality should be extended to sub-classes as well.
So can we reach consensus on this, or do we need a BDFL pronouncement?
I don't have a clear picture of what the consensus currently looks like :-)
If we're going for for a solution that implements the hook awareness for all __<typename>__ hooks, I'd be +1 on that. If we only touch the __unicode__ case, we'd only be created yet another special case. I'd vote -0 on that. [...]
Here's the patch that implements this for int/long/float/unicode: http://www.python.org/sf/1109424 Note that complex already did the right thing. For int/long/float this is implemented in the following way: Converting an instance of a subclass to the base class is done in the appropriate slot of the type (i.e. intobject.c::int_int() etc.) instead of in PyNumber_Int()/PyNumber_Long()/PyNumber_Float(). It's still possible for a conversion method to return an instance of a subclass of int/long/float. Bye, Walter Dörwald