Building RESTful APIs with Flask: A Step-by-Step Tutorial
Hevo with its minimal learning curve can be set up in just a few minutes allowing the users to load data without having to compromise performance. In that preflight, the browser sends headers that indicate the HTTP method and headers that will be used in the actual request. Django REST framework sends back restful api python flask a JSON response with the three countries you added earlier. The response above is formatted for readability, so your response will look different. This serializer, CountrySerializer, subclasses serializers.ModelSerializer to automatically generate JSON content based on the model fields of Country.
As in the previous example, our application returns a “Hello, world!” message. We will start improving it in a second, but first, let’s create an executable file called bootstrap.sh in the root directory of our application. The endpoint that accepts new incomes has also been refactored. The addition of IncomeSchema to load an instance of Income depending on the JSON data given by the user was the update to this Flask API. You just added the new Income to the transactions list because it interacts with instances of Transaction and its subclasses. Python offers a range of options for building RESTful APIs, with Flask and FastAPI being two popular choices.
Bootstrapping a Flask Application
See Flask’s license for legal information governing this project. This part of the documentation will show you how to get started in using
Flask-RESTful with Flask. To check that this script is working correctly, we run ./bootstrap.sh to get similar results as when executing the “Hello, world!” application. First and foremost, we will need to install some dependencies on our development machine. We will need to install Python 3, Pip (Python Package Index), and Flask.
Similar to Java packages and C# namespaces, modules in Python are files organized in directories that other Python scripts can import. To create a module on a Python application, we need to create a folder and add an empty file called __init__.py. Even though Django is older and has a slightly more extensive community, Flask has its strengths. From the ground up, Flask was built with scalability and simplicity. Flask applications are known for being lightweight, mainly compared to their Django counterparts. Flask developers call it a microframework, where micro (as explained here) means that the goal is to keep the core simple but extensible.
Easy-breezy REST API in Python
Using OpenAPI with the Swagger UI offers a nice, clean way to create the API URL endpoints. So far, you’ve only created one endpoint to serve all people. In the next section, you’ll add additional endpoints to create, update, and delete people in your collection. Your server will run read_all() when it receives an HTTP request to GET /api/people. The return value of read_all() is a list of dictionaries with information about a person. You import the Flask module, giving the application access to the Flask functionality.
- In this section, you’ll look at three popular frameworks for building REST APIs in Python.
- First, this request could take optional pagination arguments, so that a client can request a portion of the list.
- I will explain what we changed from the original API to get it working with CORS.
- You also want to include an appropriate status code in your response.
- We won’t dive into validation in this article, as it will be the subject of another one.
Besides that, we have also changed the implementation of both methods that deal with incomes. For the endpoint used to retrieve incomes, we defined an instance of IncomeSchema to produce a JSON representation of incomes. We also used filter to extract incomes only from the transactions list. You need to remove the endpoint that returned “Hello, world! You replaced it with an endpoint that responds to HTTP GET queries for incomes and another that responds to HTTP POST requests for new incomes. The @app.route annotation indicates that these endpoints listen for requests on the /incomes endpoint.
Building your first RESTful API with Python Flask
One difference is that you also send requestBody to the server. After all, you need to tell Flask the information that it needs to create a new person. Another difference is operationId, which you set to people.create. Any time the configuration file changes, the Swagger UI changes as well.
You’re also using a 201 HTTP status code, which is a success response that indicates the creation of a new resource. Before you define new API paths in swagger.yml, you’ll add a new block for components. Components are building blocks in your OpenAPI specification that you can reference from other parts of your specification. Currently you have a REST API running with a single URL endpoint. Your Flask app knows what to serve based on your API specification in swagger.yml.