写一个python的学生信息管理系统，要完整的代码，要求能存储学号、姓名、联系方式、性别、入学年份，要求有单独的录入学生成绩的模块，要录入python，Java，网络编程课的成绩

好的，以下是一个简单的Python学生信息管理系统的完整代码，包括了学生信息的录入、查看、修改和删除功能，以及成绩录入和查看功能。代码中使用了文件存储数据，可以在程序退出后保存数据，也可以在程序启动时读取已有数据。

# -*- coding:utf-8 -*-
import os


def display_menu():
    """显示菜单"""
    print('===============================')
    print('=========学生信息管理系统========')
    print('===============================')
    print('1. 录入学生信息')
    print('2. 查看学生信息')
    print('3. 修改学生信息')
    print('4. 删除学生信息')
    print('5. 录入学生成绩')
    print('6. 查看学生成绩')
    print('0. 退出系统')
    print('===============================')


def input_student():
    """录入学生信息"""
    print('请输入学生信息，按Q返回上级菜单')
    students = []
    while True:
        name = input('请输入姓名：')
        if name.upper() == 'Q':
            return
        if not name:
            print('姓名不能为空！')
            continue
        std_no = input('请输入学号：')
        if not std_no:
            print('学号不能为空！')
            continue
        if len(std_no) != 8:
            print('学号必须是8位数字！')
            continue
        if not std_no.isdigit():
            print('学号必须是数字！')
            continue
        while True:
            sex = input('请输入性别（男/女）：')
            if sex.upper() in ('M', '男'):
                sex = '男'
                break
            elif sex.upper() in ('F', '女'):
                sex = '女'
                break
            elif sex.upper() == 'Q':
                return
            else:
                print('性别输入有误，请重新输入！')
        phone = input('请输入联系方式：')
        if not phone:
            print('联系方式不能为空！')
            continue
        if len(phone) != 11:
            print('联系方式必须是11位数字！')
            continue
        if not phone.isdigit():
            print('联系方式必须是数字！')
            continue
        while True:
            year = input('请输入入学年份（4位数字）：')
            if year.upper() == 'Q':
                return
            if not year.isdigit():
                print('入学年份必须是数字！')
                continue
            if len(year) != 4:
                print('入学年份必须是4位数字！')
                continue
            break
        student = {
            'name': name,
            'std_no': std_no,
            'sex': sex,
            'phone': phone,
            'year': year,
            'courses': {
                'Python': '',
                'Java': '',
                '网络编程': ''
            }
        }
        students.append(student)
        print('学生信息录入成功！\n')

        if input('是否继续录入（Y/N）：').upper() == 'N':
            break
    save_students(students)


def save_students(students):
    """保存学生信息"""
    with open('students.txt', 'w', encoding='utf-8') as f:
        for student in students:
            f.write(','.join([
                student['name'],
                student['std_no'],
                student['sex'],
                student['phone'],
                student['year'],
                student['courses']['Python'],
                student['courses']['Java'],
                student['courses']['网络编程'],
            ]))
            f.write('\n')


def load_students():
    """加载学生信息"""
    if not os.path.exists('students.txt'):
        return []
    students = []
    with open('students.txt', 'r', encoding='utf-8') as f:
        for line in f:
            data = line.strip().split(',')
            student = {
                'name': data[0],
                'std_no': data[1],
                'sex': data[2],
                'phone': data[3],
                'year': data[4],
                'courses': {
                    'Python': data[5],
                    'Java': data[6],
                    '网络编程': data[7]
                }
            }
            students.append(student)
    return students


def show_students():
    """显示学生信息"""
    students = load_students()
    if not students:
        print('暂无学生信息！\n')
    else:
        print('学生信息如下：')
        print('-' * 60)
        print('{:<10}{:<10}{:<10}{:<15}{:<10}{:<10}{:<10}{:<10}'.format('姓名', '学号', '性别', '联系方式', '入学年份', 'Python', 'Java', '网络编程'))
        print('-' * 60)
        for student in students:
            print('{:<10}{:<10}{:<10}{:<15}{:<10}{:<10}{:<10}{:<10}'.format(
                student['name'],
                student['std_no'],
                student['sex'],
                student['phone'],
                student['year'],
                student['courses']['Python'],
                student['courses']['Java'],
                student['courses']['网络编程'],
            ))
        print('-' * 60)


def find_student(std_no):
    """查找学生信息"""
    students = load_students()
    for student in students:
        if student['std_no'] == std_no:
            return student
    return None


def update_student():
    """修改学生信息"""
    std_no = input('请输入要修改的学生学号：')
    student = find_student(std_no)
    if not student:
        print('未找到该学生信息！\n')
        return

    name = input('请输入姓名（{}）：'.format(student['name']))
    if name:
        student['name'] = name

    sex = input('请输入性别（{}）：'.format(student['sex']))
    if sex:
        student['sex'] = sex

    phone = input('请输入联系方式（{}）：'.format(student['phone']))
    if phone:
        student['phone'] = phone

    year = input('请输入入学年份（{}）：'.format(student['year']))
    if year:
        student['year'] = year

    save_students(load_students())
    print('学生信息修改成功！\n')


def delete_student():
    """删除学生信息"""
    std_no = input('请输入要删除的学生学号：')
    student = find_student(std_no)
    if not student:
        print('未找到该学生信息！\n')
        return

    students = load_students()
    students.remove(student)
    save_students(students)
    print('学生信息删除成功！\n')


def input_score():
    """录入学生成绩"""
    print('请输入学生成绩，按Q返回上级菜单')
    while True:
        std_no = input('请输入学生学号：')
        if std_no.upper() == 'Q':
            return
        student = find_student(std_no)
        if not student:
            print('未找到该学生信息，请重新输入！')
            continue
        python = input('请输入Python课程成绩：')
        if python.upper() == 'Q':
            return
        if not python.isdigit():
            print('输入成绩有误，请重新输入！')
            continue
        java = input('请输入Java课程成绩：')
        if java.upper() == 'Q':
            return
        if not java.isdigit():
            print('输入成绩有误，请重新输入！')
            continue
        network = input('请输入网络编程课程成绩：')
        if network.upper() == 'Q':
            return
        if not network.isdigit():
            print('输入成绩有误，请重新输入！')
            continue
        student['courses']['Python'] = python
        student['courses']['Java'] = java
        student['courses']['网络编程'] = network
        save_students(load_students())
        print('成绩录入成功！\n')

        if input('是否继续录入（Y/N）：').upper() == 'N':
            break


def show_score():
    """显示学生成绩"""
    students = load_students()
    if not students:
        print('暂无学生信息！\n')
    else:
        print('学生成绩如下：')
        print('-' * 50)
        print('{:<10}{:<10}{:<10}{:<10}'.format('姓名', '学号', 'Python', 'Java', '网络编程'))
        print('-' * 50)
        for student in students:
            print('{:<10}{:<10}{:<10}{:<10}{:<10}'.format(
                student['name'],
                student['std_no'],
                student['courses']['Python'],
                student['courses']['Java'],
                student['courses']['网络编程'],
            ))
        print('-' * 50)


def main():
    while True:
        display_menu()
        choice = input('请选择操作（0-6）：')
        if choice == '1':
            input_student()
        elif choice == '2':
            show_students()
        elif choice == '3':
            update_student()
        elif choice == '4':
            delete_student()
        elif choice == '5':
            input_score()
        elif choice == '6':
            show_score()
        elif choice == '0':
            print('感谢使用学生信息管理系统，再见！')
            break
        else:
            print('输入有误，请重新输入！')


if __name__ == '__main__':
    main()

希望对你有所帮助！