编写完整代码：实现学生类（学号、姓名、性别、年龄、班级），成绩类（学号，课程编号，成绩）、课程类（课程编号，课程名称，学分）并实现这三类的增删改查 Python

当然，我可以帮你编写一个简单的Python代码示例，用于实现学生、成绩和课程这三个类，并提供基本的CRUD操作。这里我们将使用面向对象的方式来进行设计：

class Student:
    def __init__(self, id, name, gender, age, class_name):
        self.id = id
        self.name = name
        self.gender = gender
        self.age = age
        self.class_name = class_name
        self.grades = {}

    def add_grade(self, course_id, score):
        self.grades[course_id] = score

    def delete_grade(self, course_id):
        if course_id in self.grades:
            del self.grades[course_id]

    def update_grade(self, course_id, new_score):
        if course_id in self.grades:
            self.grades[course_id] = new_score

    def view_grades(self):
        return self.grades


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


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


# 示例数据
student1 = Student(1, "张三", "男", 18, "一班")
course1 = Course(1, "数学", 4)
grade1 = Grade(student1, course1, 90)

# 增加一个成绩到学生
student1.add_grade(course1.id, grade1.score)

# 查看学生的所有成绩
print(student1.view_grades())

# 删除成绩
student1.delete_grade(course1.id)

# 更新成绩
new_score = 95
student1.update_grade(course1.id, new_score)

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