下载的txt文件被视为html，但不包括空行

Question

I've a Python/Flask app that is working ok locally. I have deployed it to the cloud (pythonanywhere) and it is all working on there as well except for a file that is being downloaded to the user that is coming as html, so the empty lines of the file are being excluded. That file is txt. When the user click on that, it opens on notepad. If opening that file in notepad++ the empty lines are there in the way it should be.

Following the Flask code to send that file:

response = make_response(result)
response.headers["Content-Disposition"] = "attachment; filename=file_to_user.txt"

If I use "inline instead of attachment", the empty lines are showed OK directly on the browser.

I've tried to add "Content type text/plain" before "Content-Disposition", but I believe that it is the default, so, no effect.

Anyone knows how could the user see that as txt file, instead of html when opening directly using notepad for example?

Answer 1

If you're just trying to send an existing file on the server, use send_from_directory .

If you're trying to make a response (for example, if you're generating data in memory, make_response defaults to text/html (it's just a shortcut which isn't applicable in your case). Create a response even more directly in order to override that using app.response_class .

This is a small example demonstrating both techniques.

from flask import Flask, send_from_directory

app = Flask(__name__)

@app.route('/file')
def download_file():
    # change app.root_path to whatever the directory actually is
    # this just serves this python file (named example.py) as plain text
    return send_from_directory(
        app.root_path, 'example.py',
        as_attachment=True, mimetype='text/plain'
    )

@app.route('/mem')
def download_mem():
    # instantiate the response class directly
    # pass the mimetype
    r = app.response_class('test data\n\ntest data', mimetype='text/plain')
    # add the attachment header
    r.headers.set('Content-Disposition', 'attachment', filename='test_data.txt')
    return r

app.run('localhost', debug=True)