Simple snippet to serve files from your #Flask #python webapplication with custom http-headers. For example adding a "accept-origin" header so that CORS (cross domain origin) requests will go through from any domain. Note that this is a rather crude (but effective!) treatment of CORS.

gistfile1.txt

# The code snippet goes into your flask app 
# Directory where we keep the data we want to serve
# Note trailing slash 
dataDir = '/home/what/ever/where/ever/you/keep/your/files/'


@app.route('/getfile/<filename>')
def getFile(filename):
    filename = dataDir + filename

    try:
        with open( filename) as file:
            blob = file.read()
    except:
        abort(404)
        pass

    r = make_response(blob)
    r.mimetype='application/json'
    r.headers['Access-Control-Allow-Origin'] = '*'

    return r