Generating CSV and XLSX reports

The DataFrame object has built-in to_csv() and to_excel() methods that save its data in CSV or XLSX files, respectively. But the main goal is to create an API service that will return these files as responses. The following implementation shows how a FastAPI service can return a CSV file containing a list of respondent profiles:

from fastapi.responses import StreamingResponse
import pandas as pd
from io import StringIO
from survey.repository.respondent import 
        RespondentRepository
@router.get("/respondents/csv", response_description='csv')
async def create_respondent_report_csv():
    repo = RespondentRepository()
    result = await repo.get_all_respondent()
    
    ids = [ item["id"] for item in result ]
    fnames = [ f'{item["fname"]}' for item in result...