使用学生信息库创建json文件时报错

#coding:utf-8

#学生信息库

import json
import logging
import os


class NotArgError(Exception):
    def __init__(self,message):
        self.message=message

class MissPathError(Exception):
    def __init__(self,message):
        self.message=message

class FormatError(Exception):
    def __init__(self,message):
        self.message=message


class StudentInfo(object):
    def __init__(self,students_path):
        self.students_path=students_path
        self.__init_path()  #可以直接在类的属性设置中使用类的方法
        self.__read()


    def __init_path(self):
        if not os.path.exists(self.students_path):  #判断路径是否存在
            raise MissPathError(f'不存在该文件：{self.students_path}')
        if not os.path.isfile(self.students_path):
            raise TypeError(f'当前的{self.students_path}不是一个文件')
        if not self.students_path.endswith('json'):  #判断文件是否为json格式
            raise FormatError('当前不是一个json文件')

    def __read(self):
        with open(self.students_path,'r',encoding='utf-8') as f:
            try:
                data=f.read()
            except Exception as e:
                raise e
        self.students = json.loads(data)

    def __save(self):
        with open(self.students_path,'w') as f:
            json_data=json.dumps(self.students)
            f.write(json_data)

    def get_all(self):
        for id_, value in self.students.items():
            print(f"学号：{id_}，姓名：{value['name']}，"
                  f"年龄：{value['age']}，性别：{value['sex']}，班级：{value['class_number']}")
        return self.students


    def check_user_info(self,**kwargs):  #在函数传参时kwargs前面需要加**将关键字参数转化为字典
        assert len(kwargs)==4,'参数必须是四个'

        if 'name' not in kwargs:   #传参后在使用时直接写kwargs表示一个所有关键字参数键值对组成的字典
            raise NotArgError('未发现学生姓名参数')
        if 'age' not in kwargs:
            raise NotArgError('缺少学生年龄参数')
        if 'sex' not in kwargs:
            raise NotArgError('缺少学生性别参数')
        if 'class_number' not in kwargs:
            raise NotArgError('缺少学生班级参数')

        name_value=kwargs['name']
        age_value=kwargs['age']
        sex_value=kwargs['sex']
        class_value=kwargs['class_number']

        if not isinstance(name_value,str):
            raise TypeError('name应该是字符串类型')
        if not isinstance(age_value,int):
            raise TypeError('age应该是整形类型')
        if not isinstance(sex_value,str):
            raise TypeError('sex应该是字符串类型')
        if not isinstance(class_value,str):
            raise TypeError('class_number应该是字符串类型')



    def add(self,**student):
        try:
            self.check_user_info(**student)   #类之中函数的相互调用需要借助self
        except Exception as e:
            raise e   #只涉及一个的增删改（没有后续的增删改）可以直接报错停止程序
        self.__add(**student)

    def adds(self,new_students):  # 批量添加
        for student in new_students:
            try:
                self.check_user_info(**student)
            except Exception as e:
                print(e,student.get('name'))
                continue    #涉及多个的增删改（要考虑后续的增删改），就必须采用continue
            self.__add(**student)

    def __add(self,**student):
        if len(self.students)==0:
            new_id=1
        else:
            new_id=max(self.students)+1
        self.students[new_id] = student

    def delete(self,student_id):
        if student_id not in self.students:
            print(f"{student_id}并不存在")
        else:
            user_info = self.students.pop(student_id)
            print(f"学号是{student_id}的{user_info['name']}同学的信息已被删除！")

    def deletes(self,ids):  #批量删除
        for id_ in ids:
            if id_ not in self.students:
                print(f"{id_}不存在于学生库中")
                continue
            deleted_student_info=self.students.pop(id_)
            print(f"学号为{id_}的学生{deleted_student_info['name']}的信息已删除")

    def update(self,student_id, **kwargs):
        if student_id not in self.students:
            print(f'并不存在{student_id}这个学号')
        try:
            self.check_user_info(**kwargs)
        except Exception as e:
            raise e
        self.students[student_id] = kwargs
        print('同学信息更新完毕')

    def updates(self,update_students):
        for student in update_students:
            try:
                id_ = list(student.keys())[0]
            except IndexError as e:
                print(e)
                continue
            if id_ not in self.students:
                print(f"学号{id_}不存在")
                continue
            user_info=student[id_]
            try:
                self.check_user_info(**user_info)  #通过**可以直接把字典传入函数（方法）中
            except Exception as e:
                print(e)
                continue
            self.students[id_]=user_info
        print('所有用户信息更新完成')


    def get_by_id(self,student_id):
        return self.students.get(student_id)

    def search_users(self,**kwargs):
        assert len(kwargs)==1,'参数数量传递错误'
        values = list(self.students.values())
        key = None
        value = None
        result = []
        if 'name' in kwargs:
            key = 'name'
            value = kwargs[key]
        elif 'sex' in kwargs:
            key = 'sex'
            value = kwargs[key]
        elif 'age' in kwargs:
            key = 'age'
            value = kwargs[key]
        elif 'class_number' in kwargs:
            key = 'class_number'
            value = kwargs[key]
        else:
            raise NotArgError('没有发现搜索的关键字')

        for user in values:  #values:[{name,age,sex,class_number},{name,age,sex,class_number}]
            if value in user[key]:  #把两边都转化为了字符串进行成员比较
                #把==改成了in就使得搜索拥有了模糊搜索效果
                result.append(user)
        return result




students={
    1:{
        'name':'dewei',
        'age':33,
        'class_number':'A',
        'sex':'boy'
    },
    2:{
        'name':'小慕',
        'age':10,
        'class_number':'B',
        'sex':'boy'
    },
    3:{
        'name':'小曼',
        'age':18,
        'class_number':'C',
        'sex':'girl'
    },
    4:{
        'name':'小高',
        'age':18,
        'class_number':'C',
        'sex':'boy'
    },
    5:{
        'name':'小云',
        'age':18,
        'class_number':'B',
        'sex':'girl'
    }
}

if __name__=='__main__':
    student_info=StudentInfo('students.json')

跟随课程过程中发现执行命令时报错（貌似与json模块本身相关？）

不知道是代码那一部分出错