学生管理系统 python实现

1.python文件

代码如下（示例）：

import os
filename='student.txt'
def main():
    while True:
        menu()
        choice=int(input('请选择操作：'))
        if choice in [0,1,2,3,4,5,6,7]:
            if choice==0:
                answer=input('您确定要退出系统吗？y/n')
                if answer=='y' or answer=='Y':
                    print('谢谢使用！')
                    break
                else:
                    continue
            elif choice==1:
                insert()
            elif choice==2:
                search()
            elif choice==3:
                delete()
            elif choice==4:
                modify()
            elif choice==5:
                sort()
            elif choice==6:
                totol()
            elif choice==7:
                show()


def menu():
    print('=============学生信息管理系统===============')
    print('-----------------功能菜单------------------')
    print('\t\t\t\t\t\t1.录入学生信息')
    print('\t\t\t\t\t\t2.查找学生信息')
    print('\t\t\t\t\t\t3.删除学生信息')
    print('\t\t\t\t\t\t4.修改学生信息')
    print('\t\t\t\t\t\t5.排序')
    print('\t\t\t\t\t\t6.统计学生总人数')
    print('\t\t\t\t\t\t7.显示所有学生信息')
    print('\t\t\t\t\t\t0.退出')
    print('------------------------------------------')


def insert():
     student_list=[]
     while True:
         id=input('请输入学生id:')
         if not id:
             break
         name=input('请输入学生姓名：')
         if not name:
             break

         try:
             english=int(input('请输入英语成绩：'))
             python=int(input('请输入python成绩：'))
             java=int(input('请输入java成绩：'))
         except:
             print('输入异常，请重新输入！')
             continue
         student={'id':id,'name':name,'english':english,'python':python,'java':java}
         student_list.append(student)
         answer=input('是否继续添加？y/n')
         if answer=='y' or answer=='Y':
             continue
         else:
             break
     save(student_list)
     print('学生信息录入完毕！')
def save(lst):
    try:
        stu_txt=open(filename,'a',encoding='utf-8')
    except:
        stu_txt=open(filename,'w',encoding='utf-8')
    for item in lst:
        stu_txt.write(str(item)+'\n')
        stu_txt.close()



def search():
    student_query=[]
    while True:
        id=''
        name=''
        if os.path.exists(filename):
            mode=input('按照id查找请输入1，按照姓名查找请输入2：')
            if mode=='1':
                id=input('请输入id：')
            elif mode=='2':
                name=input('请输入姓名：')
            else:
                print('输入有误，请重新输入')
                search()
            with open(filename,'r',encoding='utf-8') as rfile:
                student=rfile.readlines()
                for item in student:
                    # 字符串转成字典类型
                    d=dict(eval(item))
                    if id!='':
                        if d['id']==id:
                            student_query.append(d)
                    else:
                        if d['name']==name:
                            student_query.append(d)
            show_student(student_query)
            student_query.clear()
            answer = input('是否继续查找？y/n')
            if answer == 'y' or answer == 'Y':
                continue
            else:
                break
        else:
            print('暂未保存学生信息')
            return

def show_student(lst):
    if len(lst)==0:
        print('没有查询到学生信息，无数据显示')
        return
    format_title='{:^6}\t{:^12}\t{:^8}\t{:^10}\t{:^10}\t'
    print(format_title.format('ID','NAME','ENG','JAVA','PYTHON'))
    format_content='{:^6}\t{:^12}\t{:^8}\t{:^10}\t{:^10}\t'
    for item in lst:
        print(format_content.format(item['id'],item['name'],item['english'],item['java'],item['python']))

def delete():
    while True:
        delid=input('请输入要删除学生的id：')
        if delid!='':
            if os.path.exists(filename):
                with open(filename,'r',encoding='utf-8') as file:
                    student_old=file.readlines()
            else:
                student_old=[]
            flag=False
            if student_old:
                with open(filename,'w',encoding='utf-8') as wfile:
                    d={}
                    for item in student_old:
                        d=dict(eval(item))
                        if d['id']!=delid:
                            wfile.write(str(d)+'\n')
                        else:
                            flag=True
                    if flag:
                        print(f'id为{delid}的信息已被删除')
                    else:
                        print(f'不存在{delid}的学生信息')
            else:
                print('无学生信息')
                break
            show()
            answer = input('是否继续删除？y/n')
            if answer == 'y' or answer == 'Y':
                continue
            else:
                break

def modify():
    show()
    if os.path.exists(filename):
        with open(filename,'r',encoding='utf-8') as rfile:
            student_old=rfile.readlines()
    else:
        return
    stuid = input('请输入学生id')
    with open(filename,'w',encoding='utf-8') as wfile:
        for item in student_old:
            d = dict(eval(item))
            if d['id'] == stuid:
                print('已找到，可修改！')
                while True:
                    try:
                        d['id'] = stuid
                        d['name'] = input('请输入姓名：')
                        d['english'] = input('请输入英语成绩：')
                        d['python'] = input('请输入python成绩：')
                        d['java'] = input('请输入java成绩：')
                    except:
                        print('输入有误，重新输入！')
                    wfile.write(str(d) + '\n')
                    print('修改成功')
                    break
            else:
                wfile.write(str(d)+'\n')
        answer = input('是否继续修改？y/n')
        if answer == 'y' or answer == 'Y':
            modify()
    show()

def sort():
    stu=[]
    with open(filename,'r',encoding='utf-8') as rfile:
        students=rfile.readlines()
    for item in students:
        stu.append(dict(eval(item)))
    stu.sort(key=lambda x:int(x['java']),reverse=False)
    show_student(stu)



def totol():
    if os.path.exists(filename):
        with open(filename,'r',encoding='utf-8') as rfile:
            stu_txt=rfile.readlines()
            if len(stu_txt)==0:
                print('没有录入学生信息')
            else:
                print(f'一共有{len(stu_txt)}名学生')
    else:
        print('暂未保存学生信息')


def show():
    student_list=[]
    if os.path.exists(filename):
        with open(filename,'r',encoding='utf-8') as rfile:
            stu_txt=rfile.readlines()
            for item in stu_txt:
                student_list.append(eval(item))
                if student_list:
                    show_student(student_list)
    else:
        print('没有录入')



if __name__ == '__main__':
    main()

2.需要在同目录中自己创建一个student.txt文件