How to count the number of subscribers - django

Question

I'm using this model to allow user to subscribe or unsubscribe to a specific game. But now I'm unsure of how to count the number of users subscribed to a specific game.
class Subscription(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
game = models.ForeignKey(Game, on_delete=models.CASCADE)
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)
is_active = models.BooleanField(default=True)
def __str__(self):
return str(self.id)
views.py:
class TitlePostListView(ListView):
model = Post
context_object_name = 'posts'
template_name = 'posts/game.html'
def get_queryset(self):
title = get_object_or_404(Game, slug=self.kwargs.get('slug'))
return Post.objects.filter(game=title).order_by('-date_published')
def get_context_data(self, **kwargs):
context = super(TitlePostListView, self).get_context_data(**kwargs)
context['game'] = get_object_or_404(Game, slug=self.kwargs.get('slug'))
context['subscription_status'] = subscription_status(self.request.user, context['game'])
return context

Answer 1

You would do something along the lines of this:
game = Game.objects.get(name="Some Game") # Gets the game obj (replace "name" with the identifier you use)
subscriptions = Subscription.objects.filter(game=game) # Filters all the subscriptions associated with the game obj above
sub_count = subscriptions.count() # Uses QuerySet method .count() to get amount of subscription instances, and avoids a potentially costly DB hit
EDIT
To get the query into your context when using ListView, you can do something like this:
class TitlePostListView(ListView):
model = Post
context_object_name = 'posts'
template_name = 'posts/game.html'
def get_queryset(self):
game = get_object_or_404(Game, slug=self.kwargs.get('slug'))
return Post.objects.filter(game=game).order_by('-date_published')
def get_context_data(self, **kwargs):
game = get_object_or_404(Game, slug=self.kwargs.get('slug'))
context = super(TitlePostListView, self).get_context_data(**kwargs)
context['game'] = game
context['subscription_status'] = subscription_status(self.request.user, context['game'])
context['sub_count'] = Subscription.objects.filter(game=game).count()
return context
And then in your template, you can use {{ sub_count }} to see the subscription count for that specified game.