range-reading-and-large-file-analysis

name: range-reading-and-large-file-analysis description: "读取多 Sheet Excel 文件，根据数据量动态选择处理策略，支持特定区域数据提取、大文件 Parquet 转换、统计分析及可视化图表生成。"

Note: This sub-skill covers one step of the Excel analysis workflow. For the full pipeline (file reading, row counting, large-file optimization, export), see the parent workflow SKILL.md.

Step1 针对特定 Sheet 进行数据清洗与空值统计。支持处理带空格的列名，并计算关键指标的缺失率。

target_sheet = "Sheet2"
target_col = "是否通过"  # 示例列名，实际根据需求替换

# 读取指定 Sheet
df_target = pd.read_excel(file_path, sheet_name=target_sheet)

# 清洗列名：去除首尾空格
df_target.columns = [str(col).strip() for col in df_target.columns]

if target_col in df_target.columns:
    null_count = df_target[target_col].isna().sum()
    print(f"'{target_col}' 列为空的数量: {null_count}")
    
    # 统计占比
    stats = df_target[target_col].value_counts(dropna=False)
    print("分类统计结果：\n", stats)
else:
    print(f"未找到目标列: {target_col}")