how to filter by name and get total quantity for all objects

The model:

class Boat(models.Model):
    name = models.CharField(max_length=100)
    quantity = models.DecimalField(max_digits=8, decimal_places=2)
    fish_type = models.CharField(max_length=50, choices=FISH_TYPE)

    def __str__(self):

See retrieving specific objects and field lookups

What "total quantity’ are you looking for?

I want to filter by name and sum the quantity of those objects.

Ok, so then you also want to see the Aggregation docs.

I read this docs, and I am trying to make a view that return the quantity sum and I can’t figure it out.
any thought on how can I implement it???

What are some of the queries you’ve tried so far?
The examples in the Cheat Sheet section should give you some ideas,