Pay Per Request in Django
I believe this is possible. 
What you can do is have a check on your video page for a certain receipt that you can add as an entry in the UserProfile model that you'll have for your django website. 
Now this receipt will only be generated when your user goes through the complete payment path which you can handle by scripts.
And as for redirection, you can have the payment processing service redirect to your receipt token generating django view that handles the addition of the user to your whitelist for that video.
Is it possible to implement this in django: In a video site, for every video a user want to watch he/she must pay a fee before watching the video. If it's possible, what's the best way to implement this. And after every successful payment, how can the user be redirected back to the particular video he paid for?