Sending data to django site
Try Django Rest Framework with angular.
You can have the Django/Django Rest as backend.
For frontend you can have angular or react.js with nodejs or python simplehttp server or grunt or gulp running. 
So  front end will communicate to django server to get data. For logging in, you could use auth-token and angular cookies.
This will also decrease the load on backend server, since backend does not have to serve html/templates
I am trying to build a django service to which numerous clients will send data. Each client will represent an authenticated user, who might be connected to the internet or not, so the client will aggregate the data and send them when a connection is available. The data should also be persisted locally so that they are accessed quickly without hitting the server. 
The nature of the data is simple. It has to do with game achievements, so each user will have a collection of achievements they have achieved. As a consequence, there are no consistency issues, as each user will be sending their own achievement stats, and no user will edit someone else's data. 
I am trying to find the most suitable medium for this. My first thought was POST HTTP requests, which the django server will handle. A python client will login and 'send' data by performing these requests. Can anyone suggest better alternatives, or give me reasons why this setup is suitable or not? 
I'd also like to know what you would suggest for a format/way to obtain the data from the client side. I was thinking json or yaml
EDIT 2: This question has been revamped after S.Lott's recommendation.