request.POST.get() in django code example
Example: request.post django
Read about request objects that your views receive: https://docs.djangoproject.com/en/dev/ref/request-response/#httprequest-objects
Also your hidden field needs a reliable name and then a value:
<input type="hidden" name="title" value="{{ source.title }}">
Then in a view:
request.POST.get("title", "")