Upload file Flask

fileupload.py

import os
from flask import Flask, request, redirect, url_for, send_from_directory
from flask_cors import CORS
from werkzeug.utils import secure_filename

UPLOAD_FOLDER = 'files'
ALLOWED_EXTENSIONS = {'pcap'}

app = Flask(__name__)
CORS(app)
app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER

def allowed_file(filename):
    return '.' in filename and \
           filename.rsplit('.', 1)[1] in ALLOWED_EXTENSIONS

@app.route('/upload', methods=['POST'])
def upload_file():
    print(request.files)
    # check if the post request has the file part
    if 'file' not in request.files:
        print('no file in request')
        return""
    file = request.files['file']
    if file.filename == '':
        print('no selected file')
        return""
    if file and allowed_file(file.filename):
        print("hello")
        filename = secure_filename(file.filename)
        file.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
        return ""
    print("end")
    return""

@app.route('/upload/<filename>', methods=['GET'])
def uploaded_file(filename):
    return send_from_directory(app.config['UPLOAD_FOLDER'],
                               filename)

if __name__ == "__main__":
    app.run(h