无法从另一个实例化该类的实例访问实例

class MyClass:
    def __init__(self):
        self.public_attribute = "I am public"
        self._protected_attribute = "I am protected"
        self.__private_attribute = "I am private"

obj1 = MyClass()
print(obj1.public_attribute)  # 可以访问
# print(obj1._protected_attribute)  # 不推荐访问，但可以访问
# print(obj1.__private_attribute)  # 无法访问

class MyClass:
    def __init__(self):
        self.__private_attribute = "I am private"

    def get_private_attribute(self):
        return self.__private_attribute

obj1 = MyClass()
print(obj1.get_private_attribute())  # 通过方法访问私有属性

class MyClass:
    def __init__(self):
        self.__data = {}

    def set_data(self, key, value):
        self.__data[key] = value

    def get_data(self, key):
        return self.__data.get(key)

obj1 = MyClass()
obj1.set_data("key1", "value1")
print(obj1.get_data("key1"))  # 通过方法访问内部数据