在Python中，setattr和getattribute是如何交互的？

根据上面的代码，结果是：

class Test():
    def __init__(self,age):
        self.age=age
    def __getattribute__(self,attribute):
        print("Initializing getattribute")
        return 6
    def __setattr__(self,attribute,value):
        print("Initializing setattr")
        return object.__setattr__(self,attribute,value)
test=Test(4)
test.age
print(test.age)

我了解每个dunder方法的调用位置，但它们真正做什么？在前面的示例中，getattribute指定属性值，如果我删除该行：

返回对象。\uuuu setattr\uuuuuu（self，attribute，value）

没有什么变化

---

那么

\uuuuu setattr\uuuuu

做什么呢？

\uuuuu getattribute\uuuuu

在尝试访问属性之前被调用。无论

\uuuu setattr\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu

如果您摆脱了
\uuuu getattribute\uuuu
：

Initializing setattr
Initializing getattribute
Initializing getattribute
6

该类行为正常，将
test.age
设置为4。如果您进一步取消对
对象的调用。\uuuu setattr\uuuuu
，那么您将获得
AttributeError
，因为
self.age=age
永远不会实际创建或设置
age
属性；它只打印初始化消息并返回：

class Test():
    def __init__(self,age):
        self.age=age
    def __setattr__(self,attribute,value):
        print("Initializing setattr")
        return object.__setattr__(self,attribute,value)

test=Test(4)
test.age
print(test.age)

导致

class Test():
    def __init__(self,age):
        self.age=age
    def __setattr__(self,attribute,value):
        print("Initializing setattr")

test=Test(4)
test.age
print(test.age)

初始化setattr
回溯（最近一次呼叫最后一次）：
文件“/Users/chepner/tmp.py”，第11行，在
测试年龄
AttributeError:“测试”对象没有属性“年龄”
这是否回答了您的问题？
Initializing setattr
Traceback (most recent call last):
  File "/Users/chepner/tmp.py", line 11, in <module>
    test.age
AttributeError: 'Test' object has no attribute 'age'