属性似乎不正确

Question

我不明白为什么最后一个断言不起作用。错误消息 "type object 'Student' has no attribute 'name'" 让我更加困惑，因为 Student 有一个名为 name 的属性。有什么解决办法吗？

class Student:

def __init__(self, name, imt_name, semester):
    self.name = name
    self.imt_name = imt_name
    self.semester = semester

def get_name(self):
    return self.name

def __str__(self):
    return ("{} [{}] in Semester {}".format(self.name, self.imt_name, self.semester))

x = property(get_name)

#asserts and test
assert type(Student) is type

student_horst = Student("Horst", "horst99", 2)
assert student_horst.name == "Horst"
assert student_horst.imt_name == "horst99"
assert student_horst.semester == 2

student_horst.semester = 3
assert student_horst.semester == 3

#this one is not working!
assert isinstance(getattr(Student, "name"), property)

Answer 1

要检查实例是否具有给定的属性（按名称），您需要使用 hasattr 函数，如下所示：

assert hasattr(student_horst, "name")

Answer 2

name 从来都不是属性，x 是

class Student:
    def __init__(self, name):
        self._name = name # this is an attribute

    @property
    def name(self): # property
        return self._name

    def get_name(self):
        return self._name

    x = property(get_name) # x is a property not _name

student = Student('Horst')
print(student._name, student.name, student.x, sep='\n')
assert isinstance(getattr(Student, 'name'), property)
assert isinstance(getattr(Student, 'x'), property)

属性似乎不正确

Property does not seem to work the right way

python

getter

assert

properties

class

属性 似乎不正确

Property does not seem to work the right way

python

getter

assert

properties

class

属性似乎不正确