基于学生类的选课系统源代码

以下是一个基于学生类的选课系统的示例代码：

class Student:
    def __init__(self, name, id):
        self.name = name
        self.id = id
        self.courses = []

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

    def drop_course(self, course):
        self.courses.remove(course)

    def list_courses(self):
        print(f"Student {self.name} ({self.id}) is enrolled in the following courses:")
        for course in self.courses:
            print(f"- {course}")

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

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

    def drop_student(self, student):
        self.students.remove(student)
        student.drop_course(self)

    def list_students(self):
        print(f"The following students are enrolled in course {self.name} ({self.code}):")
        for student in self.students:
            print(f"- {student.name} ({student.id})")

# Example usage
if __name__ == "__main__":
    s1 = Student("Alice", 123)
    s2 = Student("Bob", 456)
    c1 = Course("Math", "MATH101")
    c2 = Course("Science", "SCI202")

    c1.add_student(s1)
    c1.add_student(s2)

    c2.add_student(s2)

    s1.list_courses()
    s2.list_courses()

    c1.list_students()
    c2.list_students()

    c1.drop_student(s2)

    s2.list_courses()
    c1.list_students()

在这个示例代码中，我们定义了两个类：学生和课程。每个学生可以选择多个课程，每个课程可以有多个学生。在学生类中，我们定义了添加课程、删除课程和列出所选课程的方法。在课程类中，我们定义了添加学生、删除学生和列出所选学生的方法。在示例代码的最后，我们演示了如何使用这些类来实现一个简单的选课系统。