I’m trying to implement a simple validator for my POST parameters

My input looks like this:

{
  "gage_id": "01010000",
  "forcing_source":"my_source",
  "forcing_path":"my_path"
}

I have the following Serializer:

class SaveTab1Serializer(Serializer):
    gage_id = CharField(min_length=1, required=True),
    forcing_source = CharField(min_length=1, required=True),
    forcing_path = CharField(min_length=1, required=True),

And I use it like this:

@api_view(['POST'])
def save_tab1(request):
    body = json.loads(request.body)
    ser = SaveTab1Serializer(data=body)
    print('serializer', ser.is_valid())
    print('errors', ser.errors)

But now matter what I do with the data, it only shows as valid with no errors. Is there more code that I need to add to the serializer to do the validation?