未绑定方法调用中的参数“分数”没有值

Question

我一直在尝试按如下方式创建一个类：

class Student:
    numberOfStudents = 0
    numberofsections = 0

    def __init__(self):
        print("Welcome to our humble organization.")

    def RegisterStudent(self, name, age, phonenumber, score):
        self.name = name
        self.age = age
        self.number = phonenumber
        self.score = score
        Student.numberOfStudents += 1
        return "Registeration is done successfully"

    def ViewStudentData(self):
        return f"Student name: {self.name}\nStudent age: {self.age}\nStudent score: {self.score}"

    @classmethod
    def Number_Of_Students(cls):
        return f"The number of students is: {Student.numberOfStudents}"

    @classmethod
    def Number_Of_Sections(cls):
        Student.numberofsections = (Student.numberOfStudents/30)
        Student.numberofsections = int(Student.numberofsections)
        return f"Numebr of sections is {Student.numberofsections}"

    @classmethod
    def View_year_Data(cls):
        return Student.Number_Of_Students(), Student.Number_Of_Sections()

当我尝试如下调用实例方法时：

Std_One = Student.RegisterStudent("Yakoza", 21, "5465164641564", 80)

它给了我这个错误：

No value for argument 'score' in unbound method call pylint(no-value-for-parameter)

错误在哪里，我看不到（用朵拉的声音）

Answer 1

通过将其称为Student.RegisterStudent(...)，您将RegisterStudent 用作类方法，即使您想创建Student 的实例。简单的解决方法是：

StdOne = Student().RegisterStudent("Yakoza", 21, "5465164641564", 80)

Student() 部分创建了您的类的一个实例，然后将其作为变量self 传递给RegisterStudent。 （您收到错误是因为在您的原始调用中，self="Yakoza"、name=21、age="5465164641564" 和 phonenumber=80；所以score 没有得到值。根本原因是它被调用的方式。）

但是，RegisterStudent 返回文本“注册成功完成”，存储在变量中没有用处。将返回行更改为return self，这是通过调用Student() 创建的对象。

def RegisterStudent(self, name, age, phonenumber, score):
    self.name = name
    self.age = age
    self.number = phonenumber
    self.score = score
    Student.numberOfStudents += 1
    print("Registeration is done successfully")
    return self

之后，您可以看到它的工作原理：

>>> print(StdOne.name)
'Yakoza'
>>> print(Student.numberOfStudents)
1

---

顺便说一句，你应该初始化__init__()中的所有实例变量，即使只是将它们设置为None，因为Python3优化了实例字典if实例变量都在__init__() 中声明。所以：

class Student:
    numberOfStudents = 0
    numberofsections = 0

    def __init__(self):
        self.name = None
        self.age = None
        self.number = None
        self.score = None
        print("Welcome to our humble organization.")