superproperty

superproperty.md

made a small script:

@dataclass
class superproperty:
    g:"func"=None
    s:"func"=None
    d:"func"=None
    def __set_name__(self, owner, name):
        iter=(b for b in owner.__mro__ if hasattr(b,name))
        next(iter)
        base=next(iter)
        orig=getattr(base,name)
        if self.g is not None:orig=orig.getter(self.g)
        if self.s is not None:orig=orig.setter(self.s)
        if self.d is not None:orig=orig.deleter(self.d)
        
        setattr(owner,name,orig)
    def getter(self,f):
        self.g=f
        return self
    def setter(self,f):
        self.s=f
        return self
    def deleter(self,f):
        self.d=f
        return self

usage:

>>> class A():
...     @property
...     def f(self):
...         print("Ag")
...     @f.setter
...     def f(self,nvalue):
...         print("As")
... 
...         
>>> class B(A):
...     @superproperty
...     def f(self):
...         print("Bg")
... 
...         
>>> class C(B):
...     @superproperty
...     def f(self):
...         print("Cg")
...     @f.deleter
...     def f(self):
...         print('Cd')
... 
...         
>>> A().f
Ag
>>> A().f=3
As
>>> B().f
Bg
>>> B().f=3
As
>>> C().f
Cg
>>> C().f=3
As
>>> del C().f
Cd