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Python Flask REST API Resourceful Blueprints Ingredient Fields

Posted by Sabine Maennel
.a{fill-rule:evenodd;}techdegree seal-36
Sabine Maennel
Treehouse Project Reviewer

Flask REST API Challenge: Marshalling methods to get a valid response

I can't solve the challenge and do not know what I am doing wrong: "Alright, now all of the methods need to be marshaled. Use marshal or marshal_with along with the ingredient_fields to make each method return a valid response. Make sure IngredientList.get returns a dictionary with a key named ingredients that holds all of the Ingredient instances. If you need a refresher, check the marshal docs."

I get " Bummer! Didn't get the right output for IngredientList.post()" I think the other two methods are working.

I would appreciate to get help with this

resources/ingredients.py 
from flask import Blueprint

from flask.ext.restful import (
    Resource, Api, reqparse, inputs,
    marshal, marshal_with, fields
)

import models


class IngredientList(Resource):
    def __init__(self):
        self.reqparse = reqparse.RequestParser()
        self.reqparse.add_argument(
            'name',
            required=True,
            location=['form', 'json']
        )
        self.reqparse.add_argument(
            'description',
            required=True,
            location=['form', 'json']
        )
        self.reqparse.add_argument(
            'measurement_type',
            required=True,
            location=['form', 'json']
        )
        self.reqparse.add_argument(
            'quantity',
            type=float,
            required=True,
            location=['form', 'json']
        )
        self.reqparse.add_argument(
            'recipe',
            type=inputs.positive,
            required=True,
            location=['form', 'json']
        )
        super().__init__()

    def get(self):
        ingredients = models.Ingredient.select()
        return ingredients

    def post(self):
        args = self.reqparse.parse_args()
        ingredient = models.Ingredient.create(**args)
        return ingredient


class Ingredient(Resource):
    def __init__(self):
          self.reqparse = reqparse.RequestParser()
          self.reqparse.add_argument(
              'name',
              required=True,
              location=['form', 'json']
          )
          self.reqparse.add_argument(
              'description',
              required=True,
              location=['form', 'json']
          )
          self.reqparse.add_argument(
              'measurement_type',
              required=True,
              location=['form', 'json']
          )
          self.reqparse.add_argument(
              'quantity',
              type=float,
              required=True,
              location=['form', 'json']
          )
          self.reqparse.add_argument(
              'recipe',
              type=inputs.positive,
              required=True,
              location=['form', 'json']
          )
          super().__init__()

    def get(self, id):
        ingredient = models.Ingredient.get(models.Ingredient.id==id)
        return ingredient

ingredients_api = Blueprint('resources.ingredients', __name__)
api = Api(ingredients_api)
api.add_resource(IngredientList, '/api/v1/ingredients')
api.add_resource(Ingredient, '/api/v1/ingredients/<int:id>')

1 Answer

Allison Schaaf
Allison Schaaf
33,322 Points
Allison Schaaf
Allison Schaaf
33,322 Points

This code passed the challenge:

from flask import Blueprint

from flask.ext.restful import (
    Resource, Api, reqparse, inputs,
    marshal, marshal_with, fields
)

import models

ingredient_fields = {
    'name': fields.String,
    'description': fields.String,
    'measurement_type': fields.String,
    'quantity': fields.Float,
    'recipe': fields.String
}


class IngredientList(Resource):
    def __init__(self):
        self.reqparse = reqparse.RequestParser()
        self.reqparse.add_argument(
            'name',
            required=True,
            location=['form', 'json']
        )
        self.reqparse.add_argument(
            'description',
            required=True,
            location=['form', 'json']
        )
        self.reqparse.add_argument(
            'measurement_type',
            required=True,
            location=['form', 'json']
        )
        self.reqparse.add_argument(
            'quantity',
            type=float,
            required=True,
            location=['form', 'json']
        )
        self.reqparse.add_argument(
            'recipe',
            type=inputs.positive,
            required=True,
            location=['form', 'json']
        )
        super().__init__()

    def get(self):
        ingredients = [marshal(ingredient, ingredient_fields)
                   for ingredient in models.Ingredient.select()]
        return {'ingredients': ingredients}

    @marshal_with(ingredient_fields)
    def post(self):
        args = self.reqparse.parse_args()
        ingredient = models.Ingredient.create(**args)
        return ingredient


class Ingredient(Resource):
    def __init__(self):
          self.reqparse = reqparse.RequestParser()
          self.reqparse.add_argument(
              'name',
              required=True,
              location=['form', 'json']
          )
          self.reqparse.add_argument(
              'description',
              required=True,
              location=['form', 'json']
          )
          self.reqparse.add_argument(
              'measurement_type',
              required=True,
              location=['form', 'json']
          )
          self.reqparse.add_argument(
              'quantity',
              type=float,
              required=True,
              location=['form', 'json']
          )
          self.reqparse.add_argument(
              'recipe',
              type=inputs.positive,
              required=True,
              location=['form', 'json']
          )
          super().__init__()

    @marshal_with(ingredient_fields)
    def get(self, id):
        ingredient = models.Ingredient.get(models.Ingredient.id==id)
        return ingredient

ingredients_api = Blueprint('resources.ingredients', __name__)
api = Api(ingredients_api)
api.add_resource(IngredientList, '/api/v1/ingredients')
api.add_resource(Ingredient, '/api/v1/ingredients/<int:id>')