Question

我试图创建一个对象，该对象可以使用类方法进行序列化和反序列化，而无需使用return语句（我不希望使用静态方法）。这是我班级的概念和一个简单的用例：

import pickle

class A:
    def __init__(self):
        self.x = 0

    def add(self):
        self.x += 1

    def serialize(self, filename):
        """Simple object serialization given a filename"""
        with open(filename, 'wb') as f:
            pickle.dump(self, f)
            print("Serialized with value of: %d" % (self.x))

    def deserialize(self, filename):
        """Simple object deserialization given a filename"""
        with open(filename, 'rb') as f:
            print("self.x before load (inside deserialize): %d" % (self.x))
            self = pickle.load(f)
            print("Deserialized value inside deserialize function: %d" % (self.x))



a1 = A()
a2 = A()

a1.add()
a1.add()

a1.serialize('a.pkl')
a2.deserialize('a.pkl')

print("Deserialized value outside: %d" % (a2.x))

但是，一旦我离开反序列化方法，self（在这种情况下，实例为a2）就不会保留其值。

运行时输出：

>> Serialized with value of: 2
>> self.x before load (inside deserialize): 0
>> Deserialized value inside deserialize function: 2
>> Deserialized value outside: 0

为什么会这样？我还在功能deepcopy中pickle.load之后尝试过deserialize，但似乎没有任何作用，我想理解为什么。

预先感谢

Answer 1

之所以不起作用，是因为您无法分配给自己（或者说：这样做不符合您的想法）。如果您想了解实际发生的情况，请尝试为self分配一些奇怪的内容，例如self = "foobar"（行为将保持不变）。

将deserialize用作类方法并将其用作“构造函数”：

@classmethod
def deserialize(cls, filename):
    """Simple object deserialization given a filename"""
    with open(filename, 'rb') as f:
        obj = pickle.load(f)
        print("Deserialized value inside deserialize function: %d" % (obj.x))
        return obj

然后像这样使用它：

a2 = A.deserialize('a.pkl')

输出：

序列化为：2
  反序列化功能中的反序列化值：2
  外部反序列化的值：2

Answer 2

对不起，您的回复很晚。泡菜将对象扁平化为字典。解决方法如下：

    def serialize(self, filename):
        """Simple object serialization given a filename"""
        with open(filename, 'wb') as f:
            pickle.dump(self.__dict__, f)
            print("Serialized with value of: %d" % (self.x))

    def deserialize(self, filename):
        """Simple object deserialization given a filename"""
        with open(filename, 'rb') as f:
            print("self.x before load (inside deserialize): %d" % (self.x))
            self.__dict__ = pickle.load(f)
            print("Deserialized value inside deserialize function: %d" % (self.x))

python中的类方法中的自我解开

2 个答案: