如何避免实例和类中的“缺少参数" [英] How do I avoid 'missing arguments' in instances and classes

问题描述

我目前正在为学校写一本应分为3个班级的:学生，老师，学校.(所有这些文件都在自己的.py文档中).

I am currently writing a for school that should have 3 classes: Student, Teacher, School. (all of them in their own .py document).

老师"课程拥有一个名称，主题和年龄的列表

The class "Teacher" holds a List of Name, subjects and Age

学生"类拥有姓名，课程和学生ID的列表

The class ''Student'' holds a List of Name, classes and student_IDs

"School"类是将两者结合在一起的类，它包含它们.

The class "School'' is the class that brings them both together, it contains them.

现在，如果我调用实例方法Student.print_list()，它将告诉我缺少一个参数.

Now if I call the instance method Student.print_list() it tells me I am lacking one Parameter.

自我是做什么的，为什么它是强制性的，如何避免不得不输入其他类的参数?

What does the self do, why is it mandatory, how do I avoid having to enter parameters from other classes?

我的第二个但同样的问题是，当我想打印出一个教师信息但必须发送一个参数时.显然，自我仍然不起作用/它接受了我给它的第一个参数.

My second but same problem is when I want to print out one Teacher info, but have to send one parameter. Obviously then the self still does not work/it takes the first parameter I give it.

我已经尝试了很多方法，但到目前为止都无济于事.我试过了:类方法(作弊)，离开自我(错误)，传递诸如list_students(False)(作弊)之类的东西.我如何合法地解决这个问题?

I have tried a bunch of things, but to no avail so far. I have tried: Class methods(cheating), leaving the self(wrong), passing anything like list_students(False)(cheating). How do I legitematly solve this problem?

student.py

student.py

class Student:
    def __init__(self, name, student_id, classes):
        self.name = name
        self.student_id = student_id
        self.classes = classes
        student_list = []
        student_list.append(Student('Nemo the Fish', '12-b-018241', 'english, maths, IT')            
    #a list of all student names etc. is entered here

school.py

school.py

import Student
class School:
    def print_list(self):
        for Student.Student in Student.student_list:
            print Student.Student.name

main.py

import school
print_list()

显然，我想要一堆名字的列表，但是我得到了缺少1个必需的位置参数:自我".我觉得我做错了，是错误地调用了该方法，因为必须有一种方法

Obviously I would want a list of a bunch of names, but I get a 'missing 1 required positional argument: self'. I feel like what I did wrong is calling the method wrongly, because there must be a way to

(自我)像应该的那样存在

have the (self) be there like its supposed to be

在不提供垃圾参数的情况下调用该方法

call the method without giving trash parameters

不要使用任何@classmethod之类的东西

not use any @classmethod thing or anything alike

推荐答案

如果我正确理解了您提供的代码，则以下操作将满足您的要求:

The following would do what you want if I understood your provided code correctly:

student.py:

student.py:

class Student:
    def __init__(self, name, student_id, classes):
        self.name = name
        self.student_id = student_id
        self.classes = classes

school.py:

school.py:

from student import Student   
class School:
    def __init__(self):
        self.student_list = []
        self.student_list.append(Student('Nemo the Fish', '12-b-018241', 'english, maths, IT'))

    def print_list(self):
        for student in self.student_list:
             print(student.name)

main.py:

from school import School()
this_school = School()
this_school.print_list() 

尽管这不是将学生列表硬编码到班级定义中的最佳方法.

Although this is not the best approach to hardcode the list of students into the class definition.

这篇关于如何避免实例和类中的“缺少参数"的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！