Return Excel/CSV File as a Response Stream FastAPI

Code base to return excel/csv file using Streaming Response in FastAPI

Returning an excel file through Streaming Response

1. Writing data to an excel stream from dataframe

   • from io import BytesIO stream = BytesIO() df.to_excel(stream, index=False, engine="openpyxl") # Note: need to install openpyxl

2. Return a Streaming Response Object from FastAPI responses module

   • from fastapi.responses import StreamingResponse response = StreamingResponse( iter([stream.getvalue()]), media_type="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", headers={ 'Content-Disposition': 'attachment;filename=sample_filename.xlsx', 'Access-Control-Expose-Headers': 'Content-Disposition' #this is optional }) return response

Returning an csv file through Streaming Response 1. Writing data to an csv stream from dataframe - from io import StringIO stream = StringIO() df.to_csv(stream, index=False)

1. Return a Streaming Response Object from FastAPI responses module
   • from fastapi.responses import StreamingResponse response = StreamingResponse( iter([stream.getvalue()]), media_type="text/csv", headers={ 'Content-Disposition': 'attachment;filename=sample_filename.csv', 'Access-Control-Expose-Headers': 'Content-Disposition' # this is optional }) return response