做一个教务管理系统的代码

教务管理系统是一个比较大型的项目，需要考虑到很多方面，包括学生信息管理、课程管理、成绩管理、教师管理等等。以下是一个简单的教务管理系统代码示例，供参考：

class Student:
    def __init__(self, id, name, grade, major):
        self.id = id
        self.name = name
        self.grade = grade
        self.major = major

class Course:
    def __init__(self, id, name, teacher):
        self.id = id
        self.name = name
        self.teacher = teacher
        self.students = []

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

class Teacher:
    def __init__(self, id, name, courses):
        self.id = id
        self.name = name
        self.courses = courses

class Grade:
    def __init__(self, student, course, score):
        self.student = student
        self.course = course
        self.score = score

class School:
    def __init__(self):
        self.students = []
        self.teachers = []
        self.courses = []
        self.grades = []

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

    def add_teacher(self, teacher):
        self.teachers.append(teacher)

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

    def add_grade(self, grade):
        self.grades.append(grade)

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

    def get_teacher(self, id):
        for teacher in self.teachers:
            if teacher.id == id:
                return teacher
        return None

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

    def get_grades(self, student=None, course=None):
        if student is None and course is None:
            return self.grades
        elif student is not None and course is None:
            return [grade for grade in self.grades if grade.student.id == student.id]
        elif student is None and course is not None:
            return [grade for grade in self.grades if grade.course.id == course.id]
        else:
            return [grade for grade in self.grades if grade.student.id == student.id and grade.course.id == course.id]

# 示例代码：
school = School()

# 添加学生
student1 = Student(1, "张三", 1, "计算机科学与技术")
student2 = Student(2, "李四", 2, "软件工程")
school.add_student(student1)
school.add_student(student2)

# 添加教师
teacher1 = Teacher(1, "王老师", [])
teacher2 = Teacher(2, "李老师", [])
school.add_teacher(teacher1)
school.add_teacher(teacher2)

# 添加课程
course1 = Course(1, "Python程序设计", teacher1)
course2 = Course(2, "Java程序设计", teacher2)
school.add_course(course1)
school.add_course(course2)

# 学生选课
course1.add_student(student1)
course2.add_student(student2)

# 教师上课
teacher1.courses.append(course1)
teacher2.courses.append(course2)

# 成绩录入
grade1 = Grade(student1, course1, 90)
grade2 = Grade(student2, course2, 85)
school.add_grade(grade1)
school.add_grade(grade2)

# 查询成绩
print(school.get_grades(student1, course1))  # 输出[<__main__.Grade object at 0x7f5b6d47ce50>]

这只是一个简单的示例，实际的教务管理系统需要考虑到更多的细节和功能。