Break django values down into count of each value - django

Question

I have a model defined similar to below
class MyModel(models.Model):
num_attempts = models.IntegerField()
num_generated = models.IntegerField()
num_deleted = models.IntegerField()
Assuming my data looked something like this:
|id|num_attempts|num_generated|num_deleted
1 1 2 0
2 2 0 1
3 3 2 1
4 3 1 2
I want to get a count of the instances at each possible value for each possible field.
For example, a return sample could look like this.
{
'num_attempts_at_1': 1,
'num_attempts_at_2': 1,
'num_attempts_at_3': 2,
'num_generated_at_0': 1,
'num_generated_at_1': 1,
'num_generated_at_2': 2,
'num_deleted_at_0': 1,
'num_deleted_at_1': 2,
'num_deleted_at_2': 1
}
This above example assumes a lot, like naming of the variables after and that it would be serialized. None of that matters but rather just how do I get it broken down like that from the database. It would be best to have this done in one query if possible.
We are using Postgres as the database.
Here is sorta close, but not quite.
qs.values_list('num_attempts','num_generated','num_deleted').annotate(Count('id'))
Gives this (not the same data as the example above)
[{'num_attempts': 4, 'id__count': 3, 'num_deleted': 3, 'num_generated': 6}, {'num_attempts': 3, 'id__count': 12, 'num_deleted': 2, 'num_generated': 2}, {'num_attempts': 2, 'id__count': 5, 'num_deleted': 0, 'num_generated': 6}]
Now with some custom python I was able to do this, but really want a database solution if possible.
def get(self, request, *args, **kwargs):
qs = self.get_queryset()
return_data = {}
for obj in qs:
count = obj.pop('id__count')
for k, v in obj.items():
key = "{}_at_{}".format(k, v)
value = return_data.get(key, 0) + count
return_data[key] = value
return Response(return_data)