Support Excel File Upload in Data Analysis Agent

Description:

The current implementation of the data-analysis-agent in community/data-analysis-agent only allows CSV files for upload and analysis:

file = st.file_uploader("Choose CSV", type=["csv"])

However, many data analysts frequently work with Microsoft Excel files (.xlsx or .xls) in addition to CSV. To enhance usability and broaden adoption, the file uploader should support both CSV and Excel formats.

Proposed Enhancement:

Update the st.file_uploader line to accept both csv and xlsx file types.

Add logic to detect the file extension and load using either:

pd.read_csv(file) for CSV

pd.read_excel(file) for Excel

Benefit:

This change will make the tool more flexible for data analysts and users who prefer working with Excel formats, which are common in business and research environments.

在 community/data-analysis-agent 中，找到 Streamlit 文件上传器及其周围的数据加载入口点。阅读当前如何处理 CSV 上传，然后验证上传器接受 CSV 和 Excel 扩展名，并且每种格式都使用相应的 pandas 加载器。完成标准是：CSV 和 Excel 文件都可以上传和分析，且不改变现有的 CSV 行为。