I'm already checking for content-type, size, and extension (Django (audio) File Validation), but I need a library to read the file and confirm that it is in fact what I hope it is (mp3 and mp4 mostly).

I've been here: http://wiki.python.org/moin/Audio/ but no luck. Been at this one for a while, am a bit lost in the woods. Relying on SO big time for this whole end of things...

Thanks in advance.

EDIT: I'm already (in Django) using UploadedFile.content_type() :

"The content-type header uploaded with the file (e.g. text/plain or application/pdf). Like any data supplied by the user, you shouldn't trust that the uploaded file is actually this type. You'll still need to validate that the file contains the content that the content-type header claims -- "trust but verify."

So, I'm already reading the header. But how can I validate the actual content of the file?

If just checking the header isn't good enough, I'd recommend using mutagen to load the file. It should throw an exception if it's not correct.

FYI, I do not think your approach is very scalable. Is it really necessary to read every byte of the file? What is your reason for not trusting the file header?