Flask File Upload

from flask import Flask
from flask import request
import os
app = Flask(__name__)

upload_folder = '/Users/tomas/Downloads/test/'

@app.route('/', methods= ['GET', 'POST'])
def upload_file():
    if request.method == 'POST':
        read_file = request.files['file']
        filename_to_save = read_file.filename

        #path = request.form['path']
        path = (filename_to_save[:2] + "/" + filename_to_save[2:4] + "/")

        dir_to_save = upload_folder + path
        if not os.path.exists(dir_to_save):
            os.makedirs(dir_to_save)

        read_file.save(dir_to_save+filename_to_save)

        return 'OK ' + filename_to_save + '\n' + dir_to_save + '\n'
    else:
        return 'BAD'

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