实验3.函数与模块综合实验

"""
成绩工具箱
覆盖：函数参数、返回值、Lambda、递归、装饰器
"""

# ---------- 装饰器 ----------
def log_call(func):
    def wrapper(*args, **kwargs):
        print(f'[日志] 调用 {func.__name__}{args}')
        result = func(*args, **kwargs)
        return result
    return wrapper


# ---------- 基础校验与计算 ----------
def is_valid_score(score, full_mark=100):
    """判断成绩是否有效；full_mark 可按满分调整。"""
    return isinstance(score, (int, float)) and 0 <= score <= full_mark


@log_call
def average(*scores):
    """接收 0 个或多个成绩，返回平均分；没有成绩时返回 0。"""
    if not scores:
        return 0
    return sum(scores) / len(scores)


def grade_of(score):
    if score >= 90:
        return 'A'
    if score >= 80:
        return 'B'
    if score >= 70:
        return 'C'
    if score >= 60:
        return 'D'
    return 'F'


def stat_scores(scores):
    """一次性返回多种统计信息，调用方用键取用。"""
    if not scores:
        return {
            'count': 0,
            'max': None,
            'min': None,
            'average': 0,
            'pass_count': 0,
        }
    return {
        'count': len(scores),
        'max': max(scores),
        'min': min(scores),
        'average': average(*scores),
        'pass_count': sum(1 for s in scores if s >= 60),
    }


def top_n(students, n=3, key=None):
    """students: 列表，元素为 (name, score) 元组。"""
    if key is None:
        key = lambda item: item[1]
    return sorted(students, key=key, reverse=True)[:n]


# ---------- 递归 ----------
def factorial(n):
    if n < 0:
        raise ValueError('n 必须是非负整数')
    if n == 0 or n == 1:
        return 1
    return n * factorial(n - 1)


def fib(n):
    if n <= 0:
        return 0
    if n == 1:
        return 1
    return fib(n - 1) + fib(n - 2)


# ---------- 组装流程 ----------
def main():
    raw_scores = [95, 82, 67, 45, 78, 90]
    valid_scores = [s for s in raw_scores if is_valid_score(s)]
    print('有效成绩：', valid_scores)
    print('平均分：', round(average(*valid_scores), 2))
    print('等级：', [grade_of(s) for s in valid_scores])

    info = stat_scores(valid_scores)
    print('统计：', info)

    students = [
        ('张三', 95),
        ('李四', 82),
        ('王五', 67),
        ('赵六', 45),
        ('钱七', 78),
    ]
    print('前三名：', top_n(students, n=3))

    # lambda + filter：筛出及格
    passed = list(filter(lambda x: x[1] >= 60, students))
    print('及格名单：', passed)

    print('5! =', factorial(5))
    print('fib(8) =', fib(8))


if __name__ == '__main__':
    main()

有效成绩： [95, 82, 67, 45, 78, 90]
[日志] 调用 average(95, 82, 67, 45, 78, 90)
平均分： 76.17
等级： ['A', 'B', 'D', 'F', 'C', 'A']
[日志] 调用 average(95, 82, 67, 45, 78, 90)
统计：{'count': 6, 'max': 95, 'min': 45, 'average': 76.166..., 'pass_count': 5}
前三名： [('张三', 95), ('李四', 82), ('钱七', 78)]
及格名单： [('张三', 95), ('李四', 82), ('王五', 67), ('钱七', 78)]
5! = 120
fib(8) = 21