Change form action to action="{{url_for('delete_images')}}". And for redirection you can use code below:
action="{{url_for('delete_images')}}"
@app.route('/delete', methods=['POST'])def delete_images(): return redirect(url_for('delete_images'))
You can get the currently requested URL by request.url:
request.url
So, to redirect to the same page use:
redirect(request.url)
This worked perfectly for me, in last line:
return redirect(request.referrer)