title: Building a secure file-manager app with Django
body: <p>I'm developing a project which is going to be a public website and it needs to get media files (digital images, audios and videos) from users and save them and I don't want users to upload malicious files into my server (I'm currently using an SFTP server for storage). So I'm looking for a solution to check file formats and allow "safe and intact" media files to be uploaded. </p>
  
  <p>Is there any python package to check some bytes of the file and say "this is a valid jpg" or "mp3" etc? Can you recommend any other solution for my problem (securing my file-manager app)?</p>