Python Nested Object Destructor (vs C++)

Question

Let's say I have two classes:

import matplotlib.pyplot as plt

class AClass:
    def __init__(self):
        self.A = SomeStuff()
        self.B = plt.figure(1)
    def SomeOtherThings(self):
        MaybeIPlotSomeThingsToThatPlotEtc
        ....

class AnotherClass:
    def __init__(self):
        self.AClassWithinAClass = AClass()
        self.B = plt.figure(2)
    def SomeOtherThings(self):
        MaybeIPlotSomeThingsToThatPlotEtc
        ....

In C++, when I put an object into another object as a POINTER to that object, I have to, HAVE to delete it in a destructor or it is a memory leak.

Question 1: In the above pseudocode, is self.B the kind of pointer that I need to delete in a destructor?

Question 2: What about the variable AClassWithinAClass? Is that a pointer that I need to delete in a destructor, or does python know to get rid of it when the AnotherClass gets deleted?

I've tried googling about pointers and stuff (Pointers in Python?) but I guess I'm nervous because python is such an implicit language.

No. There are no pointers in Python, and memory is managed for you. — juanpa.arrivillaga, Sep 21 '17 at 00:22
And if by destructor you are referring to `__del__` the **don't implement it** because messing with that could very well lead to memory leaks. — juanpa.arrivillaga, Sep 21 '17 at 00:23

score 0 · Answer 1 · answered Sep 21 '17 at 00:22

In both of these cases you do not need to explicitly call a destructor method. Python uses garbage collection to manage memory. To maintain this it uses reference counting. Python will keep a count of how many variables reference a particular object. However, if Python has a variable that is not referenced by anything it will free the memory. I'm certainly not an expert on the internal memory management of Python but that's my understanding.

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Python Nested Object Destructor (vs C++)

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