将三名学生的学号、姓名、班级信息、3门课程成绩、平均成绩，输出到一个f1文件中。将这3个学生按照平均成绩从高到低排序后，输出到f2文件中

下面是一个Python实现的示例代码，供参考：

# 定义学生类
class Student:
    def __init__(self, id, name, cls, score1, score2, score3):
        self.id = id
        self.name = name
        self.cls = cls
        self.score1 = score1
        self.score2 = score2
        self.score3 = score3
        self.avg_score = (score1 + score2 + score3) / 3

# 创建三个学生对象
stu1 = Student("001", "张三", "一班", 85, 90, 92)
stu2 = Student("002", "李四", "一班", 91, 89, 87)
stu3 = Student("003", "王五", "一班", 78, 86, 92)

# 将学生信息写入f1文件
with open("f1", "w") as f1:
    for stu in [stu1, stu2, stu3]:
        f1.write(stu.id + " " + stu.name + " " + stu.cls + " ")
        f1.write(str(stu.score1) + " " + str(stu.score2) + " " + str(stu.score3) + " ")
        f1.write(str(stu.avg_score) + "\n")

# 按照平均成绩从高到低排序
students = [stu1, stu2, stu3]
students.sort(key=lambda x: x.avg_score, reverse=True)

# 将排序后的学生信息写入f2文件
with open("f2", "w") as f2:
    for stu in students:
        f2.write(stu.id + " " + stu.name + " " + stu.cls + " ")
        f2.write(str(stu.score1) + " " + str(stu.score2) + " " + str(stu.score3) + " ")
        f2.write(str(stu.avg_score) + "\n")

以上代码会生成两个文件：f1 和 f2。其中，f1 文件包含所有学生的信息，f2 文件按照平均成绩从高到低排序后输出学生信息。您可以根据需要修改输出的文件名和路径。