Superclass static method name from subclass

[Thomas Passin]

On 11/13/2022 7:27 AM, Axy via Python-list wrote:
> On 11/11/2022 16:21, Ian Pilcher wrote:
>> Is it possible to access the name of a superclass static method, when
>> defining a subclass attribute, without specifically naming the super-
>> class?

A instance's __bases__ attribute is a sequence that contains all its 
base classes. So:

class A:
     @staticmethod
     def double(n):
         return 2 * n

class B(A):
     def parent_method(self, n):
         par = self.__class__.__bases__[0]  # For single inheritance
         return par.double(n)

b = B()
print(b.parent_method(3))  # 6

#  or
print(b.__class__.__bases__[0].double(4)) # 8


>> Contrived example:
>>
>>   class SuperClass(object):
>>       @staticmethod
>>       def foo():
>>           pass
>>
>>   class SubClass(SuperClass):
>>       bar = SuperClass.foo
>>             ^^^^^^^^^^
>>
>> Is there a way to do this without specifically naming 'SuperClass'?
>>
> There is, but it's weird. I constructed classes from yaml config so I 
> did not even know the name of super class but I wanted similar things 
> for my clabate templates and I implemented superattr() which works for me:
> 
> class BasePage:
> 
>      body = '<p>Hello</p>'
> 
> class MySpecificPage(BasePage):
> 
>      body = superattr() + '<p>World<p/>'
> 
> Actually, it's suboptimally elegant code. Artistic code, to be clear, as 
> if you looked at modern art and thought: WTF? Also, it's specific for 
> templates only and supports only __add__.
> 
> But I think the approach can be extended to a general superclass() if 
> you log __getattr__ calls and apply them in __get__ method same way.
> 
> I realize this reply is not an immediate help and probably won't help, 
> but there's always a way out.
> 
> Axy.
> 
> Here's the code:
> 
> 
> class  superattr:
>      '''
> This is a descriptor that allows extending attributes in a simple and 
> elegant way:
> 
> my_attr = superattr() + some_addition_to_my_attr
> '''
>      def  __init__(self):
>          self.additions  =  []
> 
>      def  __set_name__(self,  owner,  name):
>          print('__set_name__',  name)
>          self.attr_name  =  name
> 
>      def  __get__(self,  obj,  objtype=None):
>          for  cls  in  obj.__class__.__mro__[1:]:
>              try:
>                  value  =  getattr(cls,  self.attr_name)
>              except  AttributeError:
>                  continue
>              for  a  in  self.additions:
>                  value  =  value  +  a
>              return  value
>          raise  AttributeError(self.attr_name)
> 
>      def  __add__(self,  other):
>          print('__add__:',  other)
>          self.additions.append(other)
>          return  self Full article: 
> https://declassed.art/en/blog/2022/07/02/a-note-on-multiple-inheritance-in-python