Published on

Run a Basic Python Flask Restful API

Authors

In this tutorial we will run a basic api using flask-restful, it will only have two routes which will be a get and post method for the purpose of demonstration.

What is Flask Restful

Flask-RESTful is an extension for Flask that adds support for quickly building REST APIs. It is a lightweight abstraction that works with your existing ORM/libraries. Flask-RESTful encourages best practices with minimal setup.

If you want to see a basic Flask API post, you can follow the link below:

Installation

Install Flask and Flask Restful:

python3 -m pip install flask
python3 -m pip install flask-restful

Code

The basic code that we have, is to have two methods available (get and post):

import flask
import flask_restful

app = flask.Flask(__name__)
api = flask_restful.Api(app)

class HelloWorld(flask_restful.Resource):
    def get(self):
        return {'hello': 'world'}

    def post(self):
        json_data = request.get_json(force=True)
        firstname = json_data['firstname']
        lastname = json_data['lastname']
        return jsonify(firstname=firstname, lastname=lastname)

api.add_resource(HelloWorld, '/')

if __name__ == "__main__":
    app.run(debug=True)

Run the Server

Run the server:

python api.py

Then make a get request:

curl http://localhost:5000/

The response should be the following:

{
    "hello": "world"
}

Then make a post request:

curl -XPOST http://localhost:5000/ -d '{"firstname": "ruan", "lastname": "bekker"}'

The response should look something like this:

{
  "firstname": "ruan",
  "lastname": "bekker"
}

Integration Tests

We can setup integration tests with unittest by creating test_api.py:

import unittest
import app as api

class TestFlaskApi(unittest.TestCase):
    def setUp(self):
        self.app = api.app.test_client()

    def test_get_method(self):
        response = self.app.get("/")
        self.assertEqual(
            response.get_json(),
            {"hello": "world"},
        )

    def test_post_method(self):
        # request payload
        payload = json.dumps({
            "firstname": "ruan",
            "lastname": "bekker"
        })

        # make request
        response = self.app.post("/", data=payload, headers={"Content-Type": "application/json"})

        # assert
        self.assertEqual(str, type(response.json['lastname']))
        self.assertEqual(200, response.status_code)

    def tearDown(self):
        # delete if anything was created
        pass

if __name__ == '__main__':
    unittest.main()

Then we can run our test with:

python -m unittest discover -p test_app.py -v

Since our first test is expecting {"hello": "world"} our test will pass, and our second test we are validating that our post request returns a 200 response code and that our lastname field is of string type.

The output of our tests will show something like this:

test_get_request (test_app.TestFlaskApi) ... ok
test_post_request (test_app.TestFlaskApi) ... ok

----------------------------------------------------------------------
Ran 2 tests in 0.009s

OK

More on Flask-Restful

This was a very basic example and their documentation provides a great tutorial on how to extend from this example. This is also a great blogpost on testing rest api's.

Thank You

Thanks for reading, if you like my content, feel free to check out my website, and subscrube to my newsletter or follow me at @ruanbekker on Twitter.

Buy Me A Coffee
Discuss on Twitter • View on GitHub