实现学生选课系统程序（包含代码）

以下是一个简单的学生选课系统程序，使用 Python 语言编写：

# 定义课程和学生类
class Course:
    def __init__(self, name, id):
        self.name = name
        self.id = id
        self.students = []

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

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

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

# 定义课程和学生列表
courses = [
    Course("计算机科学", "CS101"),
    Course("数学", "MATH101"),
    Course("英语", "ENG101")
]

students = [
    Student("小明", "001"),
    Student("小红", "002"),
    Student("小刚", "003")
]

# 显示课程列表
def show_courses():
    print("可选课程:")
    for course in courses:
        print(f"{course.name} ({course.id})")

# 显示学生列表
def show_students():
    print("学生列表:")
    for student in students:
        print(f"{student.name} ({student.id})")

# 学生选课
def enroll_course():
    show_courses()
    course_id = input("请输入要选的课程编号: ")
    course = None
    for c in courses:
        if c.id == course_id:
            course = c
            break
    if not course:
        print("未找到该课程")
        return
    show_students()
    student_id = input("请输入要选课的学生编号: ")
    student = None
    for s in students:
        if s.id == student_id:
            student = s
            break
    if not student:
        print("未找到该学生")
        return
    if course in student.courses:
        print("该学生已选该课程")
    else:
        student.add_course(course)
        course.add_student(student)
        print(f"{student.name} 选了 {course.name}")

# 显示学生选课情况
def show_enrollments():
    print("学生选课情况:")
    for course in courses:
        print(f"{course.name} ({course.id}):")
        for student in course.students:
            print(f"- {student.name} ({student.id})")

# 主程序
while True:
    print("请输入数字选择操作:")
    print("1. 显示课程列表")
    print("2. 显示学生列表")
    print("3. 学生选课")
    print("4. 显示学生选课情况")
    print("0. 退出")
    choice = input()
    if choice == "1":
        show_courses()
    elif choice == "2":
        show_students()
    elif choice == "3":
        enroll_course()
    elif choice == "4":
        show_enrollments()
    elif choice == "0":
        break
    else:
        print("无效输入，请重新输入")

运行该程序后，可按照提示进行操作，包括显示课程列表、显示学生列表、学生选课和显示学生选课情况等。