从 web 下载文件到 flask 服务器

Question

My flask app should download files from urls which are posted to my app by a json object. The files should be downloaded for further processing. I do not get an error message. A lot of tutorials are about how a user uploads a file, but this is not my case. Can anyone help?

import os


from flask import Flask, request, jsonify
import urllib.request as web

app = Flask(__name__)
download_folder=os.path.join(app.instance_path,'downloads')
app.config['DOWNLOAD_FOLDER'] = download_folder


@app.route('/syncaudio', methods=['POST'])
def syncaudio():
    files = request.get_json(force=True)

    for file_url in files['syncFileUrls']:
        local_file = os.path.join(app.config['DOWNLOAD_FOLDER'], file_url.rsplit('/')[-1])
        web.urlretrieve(file_url, local_file)


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

Answer 1

urlretrieve(file_url,local_file) is the right way of doing it, there is nothing specific to Flask.

I suggest you to try in a Python interpreter to see if that works:

>>> import urllib.request
>>> urllib.request.urlretrieve('http://some/url', '/some/file/location.txt')

If that works, this means your code is never getting executed.

You may want to print the value of files to see if the list is not empty.

Answer 2

I found the solution!

for downloading FROM web TO flask server I do not need to create a folder like this:

download_folder=os.path.join(app.instance_path,'downloads') app.config['DOWNLOAD_FOLDER'] = download_folder

I just have to create a download folder via:

os.makedirs('downloads')

really simpel:)