Define your presenter by creating a file api/presenters/SwordPresenter: 
from .BasePresenter import BasePresenter

class SwordPresenter(BasePresenter):
    default_attributes = [
        'id',
        'name',
        'strength',
    ]
By default, whenever a sword is being returned in an API response, it will return a sword object in JSON format with the id, name, and strenght keys.

​
Register different formats for different actions

If you want the resource to return different data, you can register unique formats and the attributes that format should return: 
from .BasePresenter import BasePresenter
from api import operations

class SwordPresenter(BasePresenter):
    default_attributes = [
        'id',
        'name',
        'strength',
    ]

SwordPresenter.register_formats([
    operations.LIST,
], [
    'id',
])
This will only return the id attribute when making an API call to collections endpoint /swords to retrieve a list of sword resources.

​
Register custom formats

You may want to define a custom format that can return specific attributes when making an API call by including the _format URL parameter. For example, you can present specific fields by calling the GET /swords?_format=all_attributes endpoint. 
from .BasePresenter import BasePresenter
from api import operations

class SwordPresenter(BasePresenter):
    default_attributes = [
        'id',
        'name',
        'strength',
    ]

SwordPresenter.register_formats([
    'all_attributes',
], [
    'created_at',
    'deleted_at',
    'id',
    'name',
    'strength',
    'team',
    'user',
])
Note: be sure to permit reading these attributes in the SwordPolicy.