title: Flask url_for() no cache
body: <p>I put some files in static directory and these files are keep updated by some back end processing. I used <code>url_for()</code> to return url to client side.</p>
  
  <p>But I found that even if I removed the old files from static directory and regenerate the updated files, it still display the content of old files on the client browser. I think the old file has been cached.</p>
  
  <p>Does anyone know how to set no-cache for the <code>url_for()</code> function?</p>
  
  <p>Thanks in advance! </p>