[Python-ideas] deferred default arguments

Thu Jul 14 06:58:54 CEST 2011

On 7/13/2011 6:43 PM, Eric Snow wrote:
> On Wed, Jul 13, 2011 at 3:36 PM, Terry Reedy<tjreedy at udel.edu> wrote:
>> On 7/13/2011 3:26 PM, Eric Snow wrote:
>>>>> class X:
>>> def f(self, name="N/A"):
>>>> print(name)
>>>>>> class Y(X):
>>> def f(self, name="N/A"):
>>> super().f(name)
>>>> I believe
>>>> class Y(X):
>> def f(self, name=None):
>> super().f(name)
>> f.__defaults__ = X.f.__defaults__
>>>> will more or less do what you want. Using 'super()' instead of 'X' does not
>> seem to work. The default replacement might be done with a function or class
>> decorator.
>> Yeah, but if the defaults of X.f get changed at runtime,

That would be *extremely* unusual. I was not sure __defaults__ was 
writable until I tried it.
-- 
Terry Jan Reedy