闻嗅复核：毛利率计算与异常识别

"""
金融风险管理 - q002
闻嗅复核基础：毛利率计算与异常识别
"""

metadata = {
    "id": "q002",
    "title": "闻嗅复核：毛利率计算与异常识别",
    "module": "闻嗅复核基础技术",
    "difficulty": "beginner",
    "data_files": ["case32_xyz_profit.csv"],
    "skills": ["毛利率计算", "异常识别", "配比原则"],
    "estimated_minutes": 8
}

# 题目描述
"""
【题目】
读取case32_xyz_profit.csv，计算XYZ公司各期毛利率：
毛利率 = (revenue - cost) / revenue

输出DataFrame，包含：period、revenue、cost、毛利率（保留4位小数）

并在最后一列"是否异常"中标记：若毛利率与2017FY毛利率相差超过0.03（3个百分点），标记为"异常"，否则为"正常"。
"""

def solve():
    import pandas as pd
    from pyodide.http import open_url
    from io import StringIO

    BASE_URL = "https://data.zuihe.com/finance/"
    df = pd.read_csv(StringIO(open_url(BASE_URL + "case32_xyz_profit.csv").read()))

    df['毛利率'] = ((df['revenue'] - df['cost']) / df['revenue']).round(4)

    base = df[df['period'] == '2017FY']['毛利率'].values[0]
    df['是否异常'] = df['毛利率'].apply(lambda x: '异常' if abs(x - base) > 0.03 else '正常')

    result = df[['period', 'revenue', 'cost', '毛利率', '是否异常']].copy()
    return result.to_string()

if __name__ == "__main__":
    print(solve())