Python编写Student类运行报AttributeError无name属性问题求助

你代码中name/uci_name/semester均为实例属性，仅在实例化时绑定到单个Student实例上，不属于Student类本身的属性。你写的assert语句尝试直接从Student类获取对应属性，自然触发AttributeError，同时assert要求属性为property类型，你当前的代码也没有定义类层面的property对象。

你需要将三个属性定义为类层面的property，常规写法采用@property装饰器实现，注意要把实例内部存储的属性名改为带_前缀的形式，避免和property重名触发无限递归：

class Student:
    def __init__(self, name, uci_name, semester):
        self._name = name
        self._uci_name = uci_name
        self._semester = semester
    
    @property
    def name(self) -> str:
        return self._name
    
    @property
    def uci_name(self) -> str:
        return self._uci_name
    
    @property
    def semester(self) -> int:
        return self._semester
    
    def __str__(self):
        return f"{self.name} [{self.uci_name}] in Semester {self.semester}"

student_tom = Student("Tom", "tom55", 3)
    
assert isinstance(getattr(Student, "name"), property)
assert isinstance(getattr(Student, "uci_name"), property)
assert isinstance(getattr(Student, "semester"), property)

如果你想保留原有get_开头的方法，也可以直接在类末尾用property()函数绑定：

class Student:
    def __init__(self, name, uci_name, semester):
        self._name = name
        self._uci_name = uci_name
        self._semester = semester
    
    def get_name(self) -> str:
        return self._name
    
    def get_uci_name(self) -> str:
        return self._uci_name
    
    def get_semester(self) -> int:
        return self._semester
    
    # 直接在类层面定义property
    name = property(get_name)
    uci_name = property(get_uci_name)
    semester = property(get_semester)
    
    def __str__(self):
        return f"{self.name} [{self.uci_name}] in Semester {self.semester}"

以上两种写法都可以通过你给出的assert校验。

内容的提问来源于stack exchange，提问作者mayn