python django动态压缩和下载

I have a checkbox form. I am trying to make it so if a user checks the "video" box and submits the form then the video files gets zipped and django generates a dynamic download that pops up on the user screen. I want the same to happen for the audio. BUT if the user selects both checkboxes and submits, the the audio and video files are combined in a zip and a download pops up for the user. I dont want any of this stored on the disk so I am using StringIO. No download popup comes upI have a checkbox form. I am trying to make it