我有一个类，它将所有创建的引用存储在一个静态列表中，如下所示：
class A:
_List = []
def __init__(self):
A._List.append(self)
def __del__(self):
A._List.remove(self)
现在，如果我执行以下操作：
a = A()
del a
a不会被删除，因为它仍然在列表中被引用。但是，如果调用析构函数，则引用将被销毁。有没有办法以某种方式强制python执行__del__方法，以便将其从静态列表中删除？
您可以使用weakref.WeakValueDictionary（或weakref.WweakKeyDictionary[/code>），它将自动删除任何不再存在的元素：
class A(object):
_instances = weakref.WeakValueDictionary()
_next_id = functools.partial(next, itertools.count())
def __init__(self):
self._instances[self._next_id()] = self
使用weakref.ref（）创建弱引用以存储在列表中。当对象不再存在时，使用回调从列表中删除条目。
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