In python using Flask, how can I write out an obje

Question

I'm using Flask and running foreman. I data that I've constructed in memory and I want the user to be able to download this data in a text file. I don't want write out the data to a file on the local disk and make that available for download.

I'm new to python. I thought I'd create some file object in memory and then set response header, maybe?

Answer 1

Streaming files to the client without saving them to disk is covered in the "pattern" section of Flask's docs - specifically, in the section on streaming. Basically, what you do is return a fully-fledged Response object wrapping your iterator:

from flask import Response

# construct your app

@app.route("/get-file")
def get_file():
    results = generate_file_data()
    generator = (cell for row in results
                    for cell in row)

    return Response(generator,
                       mimetype="text/plain",
                       headers={"Content-Disposition":
                                    "attachment;filename=test.txt"})