Python似乎将实例属性视为类属性

class MyClass:
    class_attr = "I am a class attribute"

    def __init__(self, instance_attr):
        self.instance_attr = instance_attr

# 创建两个实例
obj1 = MyClass("Instance attribute 1")
obj2 = MyClass("Instance attribute 2")

# 访问类属性
print(MyClass.class_attr)  # 输出：I am a class attribute
print(obj1.class_attr)     # 输出：I am a class attribute
print(obj2.class_attr)     # 输出：I am a class attribute

# 修改类属性的值
MyClass.class_attr = "Updated class attribute"

# 访问修改后的类属性
print(MyClass.class_attr)  # 输出：Updated class attribute
print(obj1.class_attr)     # 输出：Updated class attribute
print(obj2.class_attr)     # 输出：Updated class attribute

# 访问和修改实例属性
print(obj1.instance_attr)  # 输出：Instance attribute 1
print(obj2.instance_attr)  # 输出：Instance attribute 2

obj1.instance_attr = "Updated instance attribute 1"
obj2.instance_attr = "Updated instance attribute 2"

print(obj1.instance_attr)  # 输出：Updated instance attribute 1
print(obj2.instance_attr)  # 输出：Updated instance attribute 2