Python remove object from registery and delete object-CodePudding

I run python code where i create multiple objects from 1 class and register these object in an IterRegistery:

class IterRegistry(type):
    def __iter__(cls):
        return iter(cls._registry)


class exampleclass(metaclass=IterRegistry):
    _registry = []

    def __init__(self, number):
        self._registry.append(self)
        self.number = number

    def destroy(self):
        if self.number == 1:
            del self


 exampleclass(1)
 exampleclass(2)

 for e in exampleclass:
     e.destroy

Now i would like an object to delist itself from the registery and destroy itself from the inside out if several requirements are met. It tried to do this by using:

del self

But that's not working.

Is there a proper way to achieve this?

CodePudding user response：

Remove itsself from the _registry list and python will garbage collect it, and iterate over exampleclass not IterRegistry

class IterRegistry(type):
    def __iter__(cls):
        return iter(cls._registry)


class exampleclass(metaclass=IterRegistry):
    _registry = []

    def __init__(self, number):
        self._registry.append(self)
        self.number = number

    def destroy(self):
        if self.number == 1:
            self.__class__._registry.remove(self)


exampleclass(1)
exampleclass(2)

for e in exampleclass:
    e.destroy()

However you don't need a metaclass:

class exampleclass():
    _registry = []

    def __init__(self, number):
        self._registry.append(self)
        self.number = number

    def destroy(self):
        if self.number == 1:
            self.__class__._registry.remove(self)

    @classmethod
    def __iter__(cls):
        return iter(cls._registry)

exampleclass(1)
exampleclass(2)

for e in exampleclass:
    e.destroy()

or even:

class exampleclass():
    registry = []

    def __init__(self, number):
        self._registry.append(self)
        self.number = number

    def destroy(self):
        if self.number == 1:
            self.__class__._registry.remove(self)

exampleclass(1)
exampleclass(2)

for e in exampleclass.registry:
    e.destroy()