CODEWITHSUNDEEP
pythoncython
Ivan Mishalkin
Ivan Mishalkin

Reputation: 1108

Delete all variables (classes) generated by class method python

For some reason, I need to be able to delete all the children (in some sense) that were originated by some method of the class. Here is an example:

class A():
    def __init__(self):
        self.a_val = 56
        self.children = list()

    def __del__(self):
        del self.children

    def gen_b(self):
        return B(self.a_val)

class B():
    def __init__(self, val):
        self.a_val = val
        self.b_val = 87

What I want is somehow to append generated class B from gen_b to A().children so that:

a_class = A()
b_generated = a_class.gen_b()
del a_class
# b_generated is also deleted

Additionally, I need this for cython (I use cdef classes), so maybe there are some solutions with __dealloc__ or other Cython specific notations. All the solutions will be appreciated.

Upvotes: 6

Views: 1329

Answers (1)

h4z3
h4z3

Reputation: 5468

What I want is somehow to append generated class B from gen_b to A().children

Just store the new element before returning it and you can do whatever you want with it - including adding to children

    def gen_b(self):
        b = B(self.a_val)
        self.children.append(b)
        return b

As for del... Please read what del actually does. The most important part is:

Deletion of a name removes the binding of that name

So if you do e.g.

>>> a_class = A()
>>> a2 = a_class
>>> del a_class

a2 still will work and target the same element (because it holds the same reference that a_class did). del just deletes the name, not the object itself.

You would need a different approach to delete those elements.

Upvotes: 5

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