#!/usr/bin/python

from flask import Flask, send_file

app = Flask(__name__)

@app.route('/')
def send_big_file():
    # make some_big_file with
    #   $ dd if=/dev/zero bs=1M count=600 of=some_big_file
    # or similar
    return send_file('some_big_file', conditional=True)

if __name__ == '__main__':
    app.run()