帮我写一个学生成绩管理系统

好的，学生成绩管理系统可以分为以下几个模块：

1. 学生信息管理模块：用于添加、修改、删除和查询学生信息，包括学生的学号、姓名、性别、联系方式等。
2. 课程信息管理模块：用于添加、修改、删除和查询课程信息，包括课程的编号、名称、学分等。
3. 成绩信息管理模块：用于添加、修改、删除和查询学生成绩信息，包括学生的学号、课程的编号、成绩等。
4. 统计分析模块：用于统计学生的平均成绩、总成绩、及格率等。

以下是一个简单的学生成绩管理系统的 Python 代码示例：

class Student:
    def __init__(self, id, name, gender, phone):
        self.id = id
        self.name = name
        self.gender = gender
        self.phone = phone

class Course:
    def __init__(self, id, name, credit):
        self.id = id
        self.name = name
        self.credit = credit

class Score:
    def __init__(self, student_id, course_id, score):
        self.student_id = student_id
        self.course_id = course_id
        self.score = score

class StudentManager:
    def __init__(self):
        self.students = []

    def add_student(self, student):
        self.students.append(student)

    def remove_student(self, student_id):
        for student in self.students:
            if student.id == student_id:
                self.students.remove(student)
                break

    def modify_student(self, student_id, name=None, gender=None, phone=None):
        for student in self.students:
            if student.id == student_id:
                if name:
                    student.name = name
                if gender:
                    student.gender = gender
                if phone:
                    student.phone = phone
                break

    def search_student(self, student_id):
        for student in self.students:
            if student.id == student_id:
                return student
        return None

class CourseManager:
    def __init__(self):
        self.courses = []

    def add_course(self, course):
        self.courses.append(course)

    def remove_course(self, course_id):
        for course in self.courses:
            if course.id == course_id:
                self.courses.remove(course)
                break

    def modify_course(self, course_id, name=None, credit=None):
        for course in self.courses:
            if course.id == course_id:
                if name:
                    course.name = name
                if credit:
                    course.credit = credit
                break

    def search_course(self, course_id):
        for course in self.courses:
            if course.id == course_id:
                return course
        return None

class ScoreManager:
    def __init__(self):
        self.scores = []

    def add_score(self, score):
        self.scores.append(score)

    def remove_score(self, student_id, course_id):
        for score in self.scores:
            if score.student_id == student_id and score.course_id == course_id:
                self.scores.remove(score)
                break

    def modify_score(self, student_id, course_id, score):
        for s in self.scores:
            if s.student_id == student_id and s.course_id == course_id:
                s.score = score
                break

    def search_score(self, student_id, course_id):
        for score in self.scores:
            if score.student_id == student_id and score.course_id == course_id:
                return score
        return None

    def average_score(self, student_id):
        total_score = 0
        count = 0
        for score in self.scores:
            if score.student_id == student_id:
                total_score += score.score
                count += 1
        if count == 0:
            return 0
        else:
            return total_score / count

    def total_score(self, student_id):
        total_score = 0
        for score in self.scores:
            if score.student_id == student_id:
                total_score += score.score
        return total_score

    def pass_rate(self, student_id):
        passed = 0
        total = 0
        for score in self.scores:
            if score.student_id == student_id:
                total += 1
                if score.score >= 60:
                    passed += 1
        if total == 0:
            return 0
        else:
            return passed / total

student_manager = StudentManager()
course_manager = CourseManager()
score_manager = ScoreManager()

while True:
    print('1. 学生信息管理')
    print('2. 课程信息管理')
    print('3. 成绩信息管理')
    print('4. 统计分析')
    print('0. 退出')
    choice = input('请选择操作：')
    if choice == '1':
        print('1. 添加学生')
        print('2. 删除学生')
        print('3. 修改学生')
        print('4. 查找学生')
        choice = input('请选择操作：')
        if choice == '1':
            id = input('请输入学号：')
            name = input('请输入姓名：')
            gender = input('请输入性别：')
            phone = input('请输入联系方式：')
            student = Student(id, name, gender, phone)
            student_manager.add_student(student)
            print('添加成功！')
        elif choice == '2':
            id = input('请输入要删除的学生的学号：')
            student_manager.remove_student(id)
            print('删除成功！')
        elif choice == '3':
            id = input('请输入要修改的学生的学号：')
            name = input('请输入新的姓名（不修改请按回车）：')
            gender = input('请输入新的性别（不修改请按回车）：')
            phone = input('请输入新的联系方式（不修改请按回车）：')
            student_manager.modify_student(id, name, gender, phone)
            print('修改成功！')
        elif choice == '4':
            id = input('请输入要查找的学生的学号：')
            student = student_manager.search_student(id)
            if student:
                print('学号：', student.id)
                print('姓名：', student.name)
                print('性别：', student.gender)
                print('联系方式：', student.phone)
            else:
                print('查找失败！')
    elif choice == '2':
        print('1. 添加课程')
        print('2. 删除课程')
        print('3. 修改课程')
        print('4. 查找课程')
        choice = input('请选择操作：')
        if choice == '1':
            id = input('请输入课程编号：')
            name = input('请输入课程名称：')
            credit = input('请输入学分：')
            course = Course(id, name, credit)
            course_manager.add_course(course)
            print('添加成功！')
        elif choice == '2':
            id = input('请输入要删除的课程编号：')
            course_manager.remove_course(id)
            print('删除成功！')
        elif choice == '3':
            id = input('请输入要修改的课程编号：')
            name = input('请输入新的课程名称（不修改请按回车）：')
            credit = input('请输入新的学分（不修改请按回车）：')
            course_manager.modify_course(id, name, credit)
            print('修改成功！')
        elif choice == '4':
            id = input('请输入要查找的课程编号：')
            course = course_manager.search_course(id)
            if course:
                print('课程编号：', course.id)
                print('课程名称：', course.name)
                print('学分：', course.credit)
            else:
                print('查找失败！')
    elif choice == '3':
        print('1. 添加成绩')
        print('2. 删除成绩')
        print('3. 修改成绩')
        print('4. 查找成绩')
        choice = input('请选择操作：')
        if choice == '1':
            student_id = input('请输入学生学号：')
            course_id = input('请输入课程编号：')
            score = input('请输入成绩：')
            score = Score(student_id, course_id, score)
            score_manager.add_score(score)
            print('添加成功！')
        elif choice == '2':
            student_id = input('请输入学生学号：')
            course_id = input('请输入课程编号：')
            score_manager.remove_score(student_id, course_id)
            print('删除成功！')
        elif choice == '3':
            student_id = input('请输入学生学号：')
            course_id = input('请输入课程编号：')
            score = input('请输入新的成绩：')
            score_manager.modify_score(student_id, course_id, score)
            print('修改成功！')
        elif choice == '4':
            student_id = input('请输入学生学号：')
            course_id = input('请输入课程编号：')
            score = score_manager.search_score(student_id, course_id)
            if score:
                print('学生学号：', score.student_id)
                print('课程编号：', score.course_id)
                print('成绩：', score.score)
            else:
                print('查找失败！')
    elif choice == '4':
        student_id = input('请输入学生学号：')
        print('平均成绩：', score_manager.average_score(student_id))
        print('总成绩：', score_manager.total_score(student_id))
        print('及格率：', score_manager.pass_rate(student_id))
    elif choice == '0':
        break
    else:
        print('无效的输入，请重新输入！')

以上代码只是一个简单的示例，可以根据具体需求进行修改和扩展。