Flask-RESTful

6.5. Flask-RESTful#

Flask-RESTful is an extension for Flask that helps you quickly build REST APIs. It adds helpful tools for:

  • Creating resources (API endpoints)

  • Handling HTTP methods (GET, POST, etc.)

  • Managing request data

  • Returning consistent JSON responses

Instead of writing everything manually with @app.route() and jsonify(), Flask-RESTful gives you a class-based structure that keeps your API logic modular and maintainable.

The main advantage of Flask-RESTful is that it reduces the amount of repetitive “boiler-plate” code that we need to write as developers.

6.5.1. Resources#

Each API endpoint is represented as a class with methods like get, post, put, and delete.

The example below:

  • creates a BookResource subclassing Resource

  • adds the add method which accepts a book_id parameter

from flask_restful import Resource

class BookResource(Resource):
    def get(self, book_id):
        return {"id": book_id, "title": "Dune"}

Note

Notice that we can return a Python dictionary directly from get and Flask-RESTful will handle serialising the dictionary for us.

6.5.2. Routing#

Instead of using @app.route(), you register resource classes with an Api object.

In the example below:

  • we create api an instance of Api

  • we register the BookResource class as the handler for the URL '/api/books/<int:book_id>'

from flask import Flask
from flask_restful import Api

app = Flask(__name__)
api = Api(app)

api.add_resource(BookResource, '/api/books/<int:book_id>')

6.5.3. Request Parameter Parsing#

Flask-RESTful comes with a class RequestParser to read the parameters from the current Flask request context and make them available inside the Resource methods.

To configure a parser:

from flask_restful import reqparse

parser = reqparse.RequestParser()
parser.add_argument('title', required=True)
parser.add_argument('author', required=True)

To use a parser:

args = parser.parse_args()

print(args['title'])
print(args['author'])