Flask 上传文件 IO错误

# -*- coding:utf-8 -*-
from flask import Flask,request,render_template,redirect,url_for
from os import path
from werkzeug.utils import secure_filename
 
app = Flask(__name__)

@app.route('/upload',methods=['GET','POST'])
def upload():
    if request.method=='POST':
        f = request.files['file']
        basepath = path.abspath(path.dirname(__file__))
        upload_path = path.join(basepath,'static/uploads')
        f.save(path.join(upload_path,secure_filename(f.filename)))
        return redirect(url_for('upload'))
    return render_template('upload.html')
 
if __name__ == '__main__':
    app.run(debug=True)

14行中加入path.join()