Python: can't invoke parent class destructor with super()

Question

I can't invoke the destructor of the Parent class from the destructor of the Child class. Please, check the code below:

class BaseClass(object):
    def __del__(self):
        print 'BaseClass->Destructor'

class DerivativeClass(BaseClass):
    def __del__(self):
        print 'DerivativeClass->Destructor'
        #Invoke destructor of the base class, it works 
        BaseClass.__del__(self)           
        #Doesn't work
        #super(DerivativeClass, self).__del__() 

instance = DerivativeClass()

When I use super(DerivativeClass, self).__del__() in DerivativeClass.__del__() I got the following error:

Exception TypeError: 'must be type, not None' in <bound method 
DerivativeClass.__del__ of <__main__.DerivativeClass object at 0xb73a682c>> ignored

QUESTION:

Why can't I use super in the destructor of the child class while it's perfectly fine in the constructor of the child class?

Answer 1

It seems that this happens only on runtime exit (because DerivativeClass is None).

This works fine:

class BaseClass(object):
    def __del__(self):
        print 'BaseClass->Destructor'

class DerivativeClass(BaseClass):
    def __del__(self):
        print 'DerivativeClass->Destructor'
        super(DerivativeClass, self).__del__() 

instance = DerivativeClass()
del instance

And this works fine too:

class BaseClass(object):
    def __del__(self):
        print 'BaseClass->Destructor'

class DerivativeClass(BaseClass):
    def __del__(self):
        print 'DerivativeClass->Destructor'
        super(type(self), self).__del__() 

instance = DerivativeClass()

Also this:

class BaseClass(object):
    def __del__(self):
        print 'BaseClass->Destructor'

class DerivativeClass(BaseClass):
    def __del__(self):
        print 'DerivativeClass->Destructor'
        super(DerivativeClass, self).__del__() 

def someScope ():
    instance = DerivativeClass()

someScope ()

---

In snippets 1 and 3, I make sure that the instance dies before the class. In snippet 2 I circumnavigate the whole issue in quite an ugly manner.