Python functools.wraps equivalent for classes

Question

When defining a decorator using a class, how do I automatically transfer over__name__, __module__ and __doc__? Normally, I would use

Answer 1

Another solution using inheritance:

import functools
import types

class CallableClassDecorator:
    """Base class that extracts attributes and assigns them to self.

    By default the extracted attributes are:
         ['__doc__', '__name__', '__module__'].
    """

    def __init__(self, wrapped, assigned=functools.WRAPPER_ASSIGNMENTS):
        for attr in assigned:
            setattr(self, attr, getattr(wrapped, attr))
        super().__init__()

    def __get__(self, obj, objtype):
        return types.MethodType(self.__call__, obj)

And, usage:

class memoized(CallableClassDecorator):
    """Decorator that caches a function's return value each time it is called.
    If called later with the same arguments, the cached value is returned, and
    not re-evaluated.
    """
    def __init__(self, function):
        super().__init__(function)
        self.function = function
        self.cache = {}

    def __call__(self, *args):
        try:
            return self.cache[args]
        except KeyError:
            value = self.function(*args)
            self.cache[args] = value
            return value
        except TypeError:
            # uncacheable -- for instance, passing a list as an argument.
            # Better to not cache than to blow up entirely.
            return self.function(*args)