用python写学生选课管理系统的代码

好的，下面是一个简单的学生选课管理系统的 Python 代码示例：

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"{self.name}'s courses:")
        for course in self.courses:
            print(course.name)

class Course:
    def __init__(self, name, id):
        self.name = name
        self.id = id
        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"{self.name}'s students:")
        for student in self.students:
            print(student.name)

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

    def add_student(self, name, id):
        student = Student(name, id)
        self.students.append(student)
        return student

    def add_course(self, name, id):
        course = Course(name, id)
        self.courses.append(course)
        return course

    def enroll(self, student, course):
        course.add_student(student)

    def drop(self, student, course):
        course.drop_student(student)

    def list_students(self):
        print("All students:")
        for student in self.students:
            print(student.name)

    def list_courses(self):
        print("All courses:")
        for course in self.courses:
            print(course.name)


# Example usage
enrollment_system = EnrollmentSystem()

# Add students
alice = enrollment_system.add_student("Alice", 1)
bob = enrollment_system.add_student("Bob", 2)
charlie = enrollment_system.add_student("Charlie", 3)

# Add courses
math = enrollment_system.add_course("Math", 101)
physics = enrollment_system.add_course("Physics", 102)
chemistry = enrollment_system.add_course("Chemistry", 103)

# Enroll students in courses
enrollment_system.enroll(alice, math)
enrollment_system.enroll(alice, physics)
enrollment_system.enroll(bob, chemistry)
enrollment_system.enroll(charlie, math)
enrollment_system.enroll(charlie, chemistry)

# List students and courses
enrollment_system.list_students()
enrollment_system.list_courses()

# List courses for each student
alice.list_courses()
bob.list_courses()
charlie.list_courses()

# List students for each course
math.list_students()
physics.list_students()
chemistry.list_students()

# Drop a course for a student
enrollment_system.drop(alice, math)
alice.list_courses()
math.list_students()

这个系统包含了三个类：学生、课程和选课系统，以及它们之间的关系和交互方法。通过创建实例并调用这些方法，可以进行学生选课和管理。