Python:确保类属性不会在公共继承树之间共享

class Parent:
    class_attribute = "I am a class attribute"

class Child(Parent):
    pass

print(Parent.class_attribute)  # 输出: I am a class attribute
print(Child.class_attribute)   # 输出: I am a class attribute
Child.class_attribute = "I am a modified class attribute"
print(Parent.class_attribute)  # 输出: I am a class attribute
print(Child.class_attribute)   # 输出: I am a modified class attribute

class Parent:
    def __init__(self):
        self.instance_attribute = "I am an instance attribute"

class Child(Parent):
    def __init__(self):
        super().__init__()
        self.instance_attribute = "I am a modified instance attribute"

parent = Parent()
child = Child()

print(parent.instance_attribute)  # 输出: I am an instance attribute
print(child.instance_attribute)   # 输出: I am a modified instance attribute