[Python-Dev] new metaclass error condition checks (original) (raw)

Thomas Wouters thomas at python.org
Fri Apr 20 15:56:02 CEST 2007

On 4/17/07, Jean-Paul Calderone <exarkun at divmod.com> wrote:

I just noticed r53997 (from some unit tests it broke), which disallowed things like this: class X(object): def repr(self): return "blah" class Y(X, type): pass class Z: metaclass = Y Making X classic eliminates the TypeError, and is probably an acceptable fix in a lot of cases (at least as long as classic classes are available). I wonder if the ability to override type special methods like this was considered when the change was made, though?

Probably not, or at least not consciously. I think the point is that 'type' and its subclasses are special enough that this warrants a separate 'X' that inherits from 'type' rather than 'object'. Reduced reusability, but how badly does this affect you in the real world, really?

-- Thomas Wouters <thomas at python.org>

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