帮我用python语言写一个具有添加、删除、修改、查询学生信息及退出系统功能的简易学生管理系统

好的，下面是一个简单的学生管理系统的Python代码：

# 定义学生类
class Student:
    def __init__(self, name, age, gender, score):
        self.name = name
        self.age = age
        self.gender = gender
        self.score = score

# 定义管理系统类
class StudentManager:
    def __init__(self):
        self.students = []

    # 添加学生信息
    def add_student(self, student):
        self.students.append(student)
        print("添加成功！")

    # 删除学生信息
    def del_student(self, name):
        for student in self.students:
            if student.name == name:
                self.students.remove(student)
                print("删除成功！")
                return
        print("查无此人！")

    # 修改学生信息
    def modify_student(self, name, age, gender, score):
        for student in self.students:
            if student.name == name:
                student.age = age
                student.gender = gender
                student.score = score
                print("修改成功！")
                return
        print("查无此人！")

    # 查询学生信息
    def query_student(self, name):
        for student in self.students:
            if student.name == name:
                print("姓名：", student.name)
                print("年龄：", student.age)
                print("性别：", student.gender)
                print("分数：", student.score)
                return
        print("查无此人！")

    # 运行管理系统
    def run(self):
        while True:
            print("=" * 30)
            print("学生管理系统")
            print("1. 添加学生信息")
            print("2. 删除学生信息")
            print("3. 修改学生信息")
            print("4. 查询学生信息")
            print("5. 退出系统")
            print("=" * 30)

            choice = input("请输入您的选择：")
            if choice == "1":
                name = input("请输入学生姓名：")
                age = input("请输入学生年龄：")
                gender = input("请输入学生性别：")
                score = input("请输入学生成绩：")
                student = Student(name, age, gender, score)
                self.add_student(student)
            elif choice == "2":
                name = input("请输入学生姓名：")
                self.del_student(name)
            elif choice == "3":
                name = input("请输入学生姓名：")
                age = input("请输入学生年龄：")
                gender = input("请输入学生性别：")
                score = input("请输入学生成绩：")
                self.modify_student(name, age, gender, score)
            elif choice == "4":
                name = input("请输入学生姓名：")
                self.query_student(name)
            elif choice == "5":
                print("感谢使用学生管理系统，再见！")
                break
            else:
                print("输入有误，请重新输入！")

# 运行管理系统
if __name__ == "__main__":
    manager = StudentManager()
    manager.run()

运行后，程序将进入学生管理系统，根据提示进行操作即可。