class Data:
def __del__(self):
print('Data.__del__')
class Node:
def __init__(self):
self.data = Data()
self.parent = None
self.children = []
def add_child(self, child):
self.children.append(child)
child.parent = self
a = Node()
del a
As a result, Data.__del__ is printed, why __del__() funtion in class Data is called?
