<每日一题>题目7：简单的学生管理系统V1.0

'''
# 学生管理系统ｖ1.0
# 添加学生的信息
# 删除学生的信息
# 修改学生的信息
# 查看学生的信息
#遍历学生的信息
#退出系统
'''
import json
#1 显示操作功能
def showinfo():
    print('*'*40)
    print("\t  　欢迎使用学生管理系统V1.0")
    print("1.添加学生的信息")
    print("2.删除学生的信息")
    print("3.修改学生的信息")
    print("4.查询学生的信息")
    print("5.遍历所有学生的信息")
    print("6.退出系统")
    print('*' * 40)

students = []

def add_student():
    print("您选择了添加学生信息功能！")
    ID = input("请输入学生学号：")
    name = input("请输入学生姓名：")
    age = input("请输入学生年龄：")
    sex = input("请输入学生性别：")
    if len(students) == 0:
        stu_info = {}
        stu_info["ID"] = ID
        stu_info["name"] = name
        stu_info["age"] = age
        stu_info["sex"] = sex
        students.append(stu_info)
        print("学生%s添加成功" % stu_info)
    else:
        for i in students:
            if i["ID"] == ID:
                print("学号重复，请查询后在进行添加！")
                break
            else:
                stu_info = {}
                stu_info["ID"] = ID
                stu_info["name"] = name
                stu_info["age"] = age
                stu_info["sex"] = sex
                students.append(stu_info)
                print("学生%s添加成功"%stu_info)
    save_students()
    main()

def alter_student():
    print("欢迎使用修改学生信息功能！")
    ID = input("请输入需要修改学生的学号:")
    leap = 0
    for i in students:
        if i["ID"] == ID:
            alter_ID = input("请输入修改后的学号:")
            for i in students:
                if i["ID"] == alter_ID:
                    print("学号重复，请查询后在进行修改！")
                    leap = 1
                    break
            if leap != 1:
                alter_name = input("请输入修改后的名字：")
                alter_sex = input("请输入修改后的性别：")
                alter_age = input("请输入修改后的年龄：")
                i["ID"] = alter_ID
                i["name"] = alter_name
                i["age"] = alter_age
                i["sex"] = alter_sex
                save_students()
        else:
            print("查无此人，请查询后在进行修改！")
            break
    main()

def del_student():
    print("您选择了删除学生信息功能！")
    ID = input("请输入需要删除学生的学号：")
    for i in students:
        if i['ID'] == ID:
            print("学生%s删除成功"%i)
            del students[students.index(i)]
            save_students()
            break
        else:
            print("输入的学号有误，请查询后重试！")
    main()

def inquire_student():
    print("欢迎使用学生查询功能：")
    inquire_ID = input("请输入查询学生学号：")
    for i in students:
        if i["ID"] == inquire_ID:
            print('查询学生信息如下',end="\n")
            print("学号：%s\t姓名：%s\t年龄:%s\t性别：%s"%(i["ID"],i["name"],i["age"],i["sex"]))
        else:
            print("查无此人")
    main()

def exit_student():
    print("真的要退出么？")
    demo = str(input("输入yes退出，输入no不退出:"))
    demo=demo.lower()
    if demo == "yes":
        return
    elif demo == "no":
        main()
    else:
        print("输入有误，重新输入")
        exit_student()

def show_student():
    print("欢迎使用遍历学生的信息功能")
    for i in students:
        print("学号：%s\t姓名：%s\t年龄:%s\t性别：%s" % (i["ID"], i["name"], i["age"], i["sex"]))
    main()

def select(key):
    if key == 1:
        add_student()
    elif key == 2:
        del_student()
    elif key == 3:
        alter_student()
    elif key == 4:
        inquire_student()
    elif key == 5:
        show_student()
    elif key == 6:
        exit_student()
    else:
        print("输入有误，请重新输入！")

def save_students():
    file = json.dumps(students,ensure_ascii=False)
    with open('students.txt','w+',encoding='utf-8') as f:
        f.write(file)

def main():
    showinfo()
    key = int(input("请选择您要进行的操作（序号）："))
    select(key)

if __name__ == '__main__':
    main()

　　运行结果：