从 python 类中添加和删除对象的问题答案

【问题标题】：Problem adding and deleting objects from python class从 python 类中添加和删除对象的问题
【发布时间】：2021-03-20 11:17:54
【问题描述】：

请有人帮我修复代码，我想创建一个学校班级并创建一个对象。之后，我想使用join函数添加学生（如果有学生则不添加并显示消息，如果不存在则添加学生），与离开功能相同（它将删除仅当存在时才从列表中）。最后，show_all 函数将显示列表中的所有值。我认为代码的结构是错误的，所以请有人帮助我

class School:
    
    def __init__(self):
        print("A class has opened!")

    def join(self, student):
        self.student = student
        if self.student not in my_school:
            print(self.student +" is a new member of the school!")
        
        else:
            print("We already have "+ self.student +".")
        
    def leave(self):
        if self.student in my_school:
            del self.student
        
        else:
            print("No such student")
            
        
    def show_all(self):
        print(my_school)

# create new object in class
my_school = School() 

# add the student if not exists only
my_school.join('Sarah') 
# delete if exists
my_school.leave("Noor")
# show all the list
my_school.show_all()

【问题讨论】：

请使用完整的错误回溯更新您的问题。

标签： python oop

【解决方案1】：

您的代码有几个错误：

当您调用 join（一个错误的方法名称，因为它已经存在）时，您会将学生重新分配给单个变量。
请假你引用的实例女巫是不可能的，因为它不存在。

这里有一些代码：

class School:
    
    def __init__(self):
        print("An instance of School was created!")
        self.students = []

    def join(self, student):
        if student not in self.students:
            self.students.append(student)
            print(student + " is a new member of the school!")
        else:
            print("We already have "+ student +".")
        
    def leave(self, student):
        if student in self.students:
            self.students.remove(student)
        else:
            print("No such student")
            
    def show_all(self):
        print(self.students)

# create new object in class
my_school = School() 

# add the student if not in students
my_school.join("Sarah")

# delete the student if in the students list
my_school.leave("Noor")

# print the students
my_school.show_all()

这绝不是好的代码，但接近你想要实现的目标。

【讨论】：