Zipping several CSV files on server using StreamingResponse in Python

Question

I am trying to create a Zip File via the StreamingResponse (so it will not be saved locally) on my server to send to the Frontend. The Zip file will contain CSV files which are converted from several Dataframes. So far I am getting the Zip file through Postman, but when I am trying to open it, I get an error message which indicates that the Zip file is corrupted: Error

The code I have written so far:

def prepare_zip(dafaframes):

outfile = io.BytesIO()
with zipfile.ZipFile(outfile, 'w') as zf:
    for n, f in enumerate(dafaframes):
        stream = io.StringIO()
        f.to_csv(stream, index=False)
        stream.seek(0)
        csv_buffer = stream.read()
        zf.writestr("{}.csv".format(n), csv_buffer)
    # Returns a csv prepared to be downloaded in the FrontEnd
    outfile.seek(0)
    response = StreamingResponse(outfile,
                                 media_type="application/x-zip-compressed"
                                 )

    response.headers["Content-Disposition"] = "attachment; filename=test.zip"

    return response

The 'dataframes' parameter is a list containing the dataframes which are supposed to be converted to CSV and be held by the Zip file.