Изменение массива результатов Flask-Restless

Я думаю, вам нужно использовать постпроцессоры, так как вам нужно изменить ответ json перед его отправкой обратно клиенту.

Хорошо, я воспроизвел вашу проблему. Теперь это работает. Вот мой код:

import flask
import flask_sqlalchemy
import flask_restless

# Create the Flask application and the Flask-SQLAlchemy object.
app = flask.Flask(__name__)
app.config['DEBUG'] = True
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:////tmp/test.db'
db = flask_sqlalchemy.SQLAlchemy(app)


# Create your Flask-SQLALchemy models as usual but with the following
# restriction: they must have an __init__ method that accepts keyword
# arguments for all columns (the constructor in
# flask_sqlalchemy.SQLAlchemy.Model supplies such a method, so you
# don't need to declare a new one).

class User(db.Model):

    __tablename__ = 'user'

    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String)
    userdetails = db.relationship('UserDetails', backref='User', lazy='dynamic')


class UserDetails(db.Model):

    __tablename__ = 'user_details'

    id = db.Column(db.Integer, primary_key=True)
    detail = db.Column(db.String)
    detail_name = db.Column(db.String)
    user_id = db.Column(db.Integer, db.ForeignKey("user.id"), nullable=False)

# Create the database tables.
db.create_all()

# Create the Flask-Restless API manager.
manager = flask_restless.APIManager(app, flask_sqlalchemy_db=db)

user = User(username='plasmy')
userdetail_0 = UserDetails(detail='A name', detail_name='Full Name' )
userdetail_1 = UserDetails(detail='[email protected]', detail_name='Email')
userdetail_2 = UserDetails(detail='An Address', detail_name='Address')
userdetail_3 = UserDetails(detail='999-999-9999', detail_name='Phone Number')


user.userdetails.append(userdetail_0)
user.userdetails.append(userdetail_1)
user.userdetails.append(userdetail_2)
user.userdetails.append(userdetail_3)

db.session.add(user)
db.session.commit()

print('USER CREATED')

def detail_sort(result, **kw):
    print('detail_sort called')
    print(result)

    for entry in result['objects']:
        entry['userdetails'] = {item['detail_name']: item['detail'] for item in
                                entry['userdetails']}
    print('MODIFIED JSON: ', result)

# Create API endpoints, which will be available at /api/<tablename> by
# default. Allowed HTTP methods can be specified as well.
# manager.create_api(Person, methods=['GET', 'POST', 'DELETE'])
# manager.create_api(Article, methods=['GET'])

manager.create_api(User, methods=['GET', 'POST', 'DELETE'],
                   postprocessors={
                       'GET_MANY': [detail_sort]
                   })
manager.create_api(UserDetails, methods=['GET'], )

# start the flask loop
app.run(use_reloader=False)

Обратите внимание, что вам нужно использовать GET_MANY и посмотреть, как реализовано detail_sort.

Без использования постпроцессора ответ будет таким:

{
  "num_results": 1, 
  "objects": [
    {
      "id": 1, 
      "userdetails": [
        {
          "detail": "A name", 
          "detail_name": "Full Name", 
          "id": 1, 
          "user_id": 1
        }, 
        {
          "detail": "[email protected]", 
          "detail_name": "Email", 
          "id": 2, 
          "user_id": 1
        }, 
        {
          "detail": "An Address", 
          "detail_name": "Address", 
          "id": 3, 
          "user_id": 1
        }, 
        {
          "detail": "999-999-9999", 
          "detail_name": "Phone Number", 
          "id": 4, 
          "user_id": 1
        }
      ], 
      "username": "plasmy"
    }
  ], 
  "page": 1, 
  "total_pages": 1
}

С постпроцессором ответ выглядит так:

{
  "num_results": 1, 
  "objects": [
    {
      "id": 1, 
      "userdetails": {
        "Address": "An Address", 
        "Email": "[email protected]", 
        "Full Name": "A name", 
        "Phone Number": "999-999-9999"
      }, 
      "username": "plasmy"
    }
  ], 
  "page": 1, 
  "total_pages": 1
}

Надеюсь это поможет.