Question

Is it possible to make a class call del() for some instances under some condition? Or turn self into None?

    class T:
        def __init__(self, arg1, arg2):
            condition=check_condition(arg1,arg2)
            if not condition:
               do_something(arg1)
            else:
               del(self) #or self=None or return None

I need to do something like this to be sure that will never exist a kind of instance.

Answer 1

I need do something like this to be sure that will never exist a kind of instance.

If you simply want to prevent the creation of such an instance, raise an exception in __init__() whenever the condition is satisfied.

This is standard protocol for signalling constructor failures. For further discussion, see Python: is it bad form to raise exceptions within __init__?