In python using Flask, how can I write out an object for download?
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"})