实验2.数据结构综合实验

{
    'id': 'S001',           # 学号，字符串
    'name': '张三',         # 姓名
    'scores': [90, 85, 78], # 三门课成绩，列表
    'tags': {'数学', '篮球'}  # 兴趣/课程标签，集合
}

"""
班级花名册
覆盖：列表、元组、字符串、集合、字典
"""

# 1）准备数据：列表 + 字典 + 集合
roster = [
    {
        'id': 'S001',
        'name': '  张三  ',
        'scores': [90, 85, 78],
        'tags': {'数学', '篮球'},
    },
    {
        'id': 'S002',
        'name': 'Li Si',
        'scores': [72, 68, 91],
        'tags': {'英语', '篮球'},
    },
    {
        'id': 'S003',
        'name': '王五',
        'scores': [55, 60, 58],
        'tags': {'数学', '英语'},
    },
    {
        'id': 'S004',
        'name': '赵六',
        'scores': [88, 92, 95],
        'tags': {'数学'},
    },
]

# 2）字符串清洗：去掉姓名两侧空白，英文统一首字母大写
for student in roster:
    raw_name = student['name']
    cleaned = raw_name.strip()
    if cleaned.isascii():
        cleaned = cleaned.title()
    student['name'] = cleaned

# 3）列表方法：新增、查找、删除
new_student = {
    'id': 'S005',
    'name': '钱七',
    'scores': [80, 80, 80],
    'tags': {'篮球'},
}
roster.append(new_student)

# 按学号查找（字典键访问）
target_id = 'S002'
found = None
for student in roster:
    if student['id'] == target_id:
        found = student
        break
print(f'查找 {target_id}：', found['name'] if found else '未找到')

# 删除指定学号的学生
remove_id = 'S003'
roster[:] = [s for s in roster if s['id'] != remove_id]
print(f'已删除 {remove_id}，剩余 {len(roster)} 人')

# 4）平均分与排序：用列表生成式提取平均分，再按平均分降序
for student in roster:
    student['average'] = sum(student['scores']) / len(student['scores'])

# 先算再排；用 sorted 生成新列表，不直接打乱原列表顺序
ranked = sorted(roster, key=lambda s: s['average'], reverse=True)
print('按平均分排名：')
for rank, student in enumerate(ranked, start=1):
    # 字符串格式化与对齐
    line = f"{rank}. {student['id']} {student['name']:<8} 平均分 {student['average']:.1f}"
    print(line)

# 5）集合运算：同时有“数学”和“篮球”的学生
math_students = {s['id'] for s in roster if '数学' in s['tags']}
basketball_students = {s['id'] for s in roster if '篮球' in s['tags']}
both = math_students & basketball_students
print('同时选数学和篮球：', sorted(both))
print('只选数学：', sorted(math_students - basketball_students))
print('选了数学或篮球：', sorted(math_students | basketball_students))

# 6）字典生成式：学号 -> 平均分
avg_map = {s['id']: round(s['average'], 1) for s in roster}
print('学号平均分表：', avg_map)

# 7）元组：用不可变三元组导出“学号、姓名、平均分”
summary = tuple((s['id'], s['name'], round(s['average'], 1)) for s in ranked)
print('摘要（元组）：', summary)

# 8）按分数段统计人数（字典 + 列表）
level_count = {'优秀': 0, '良好': 0, '及格': 0, '不及格': 0}
for student in roster:
    avg = student['average']
    if avg >= 90:
        level_count['优秀'] += 1
    elif avg >= 80:
        level_count['良好'] += 1
    elif avg >= 60:
        level_count['及格'] += 1
    else:
        level_count['不及格'] += 1
print('分数段人数：', level_count)