Clean way to disable `__setattr__` until after initialization

You are catching all assignments, which prevents the constructor from assigning self.value. You can use self.__dict__ to access the instance dictionary. Try:

class Wrapper:    def __init__(self, value):        self.__dict__['value'] = value    def __setattr__(self, name, value):        setattr(self.value, name, value)

Another way using object.__setattr__:

class Wrapper(object):    def __init__(self, value):        object.__setattr__(self, 'value', value)    def __setattr__(self, name, value):        setattr(self.value, name, value)

A way to disable the __setattr__ until after initialization without changing the self.value = value syntax in the __init__ method is covered here. In short, embed knowledge of initialization in the object and use it in the __setattr__ method. For your Wrapper:

class Wrapper:    __initialized = False    def __init__(self, value):        self.value = value        self.__initialized = True    def __setattr__(self, name, value):        if self.__initialized:            # your __setattr__ implementation here        else:            object.__setattr__(self, name, value)

With __getattr__ overridden as well::

class Wrapper:    def __init__(self,wrapped):        self.__dict__['wrapped'] = wrapped    def __setattr__(self,name,value):        setattr(self.__dict__['wrapped'],name,value)    def __getattr__(self,name):        return getattr(self.__dict__['wrapped'],name)class A:    def __init__(self,a):        self.a = awa = Wrapper(A(3))#wa.a == wa.wrapped.a == 3