Create REST APIs in Python using Flask

There is a special decorator called before_request just for this. Instead of the default 200 status code which says OK, we are sending the status code 418 which says I’M A TEAPOT. Flask is a microframework for Python that is used for creating web applications ranging from websites, blogs, to any commercial-scale web applications. This means, Flask is equipped with and supports lots of tools and libraries to develop a web application easily.

However, it is not always possible to develop an entire application to test your APIs. For that purpose, we have another tool, Postman, that will help us test our endpoints once we are done with the development. I would advise
you to download and install Postman
on your machine before continuing the next part of the article. This command creates a new folder in your current directory called countryapi.

A brief introduction to the Flask microframework

They use Python type annotations to enforce the data type for each field in the class. This allows FastAPI to automatically generate JSON, with the correct data types, for API endpoints. This application uses the features of FastAPI to build a REST API for the same country data you’ve seen in the other examples. As you’ve seen, Django REST framework is a great option for building REST APIs, especially if you have an existing Django project and you want to add an API.

• Now, in order to consume these APIs, also known as endpoints, we need a client to place requests from.
• The response contains the information for the first Country.
• Python provides some great tools not only to get data from REST APIs but also to build your own Python REST APIs.
• REST provides a set of constraints for software architecture to promote performance, scalability, simplicity, and reliability in the system.

GET is one of the most common HTTP methods you’ll use when working with REST APIs. This method allows you to retrieve resources from a given API. GET is a read-only operation, so you shouldn’t use it to modify an existing resource. The return value from a function in a Flask app should be JSON serializable. This function wraps json.dumps() to turn the JSON output into a Response object with application/json mime-type. The “micro” in microframework means Flask aims to keep the core simple but extensible.

Improving the web service interface

That is, you will install Docker in the future and run the software in environments such as production and staging. This will be the core module, including all of your RESTful APIs. Let’s make a new directory, manca, inside the one made for the application. If you’re using a different Python version, the command above can return a different result. What matters is that the output starts with Python 3 rather than Python 2. If the latter is the case, you can attempt the python3 —version.

Once the views are created, they need to be mapped to the appropriate URLs or endpoints. To do this, Django REST framework provides a DefaultRouter that will automatically generate URLs for a ModelViewSet. This returns the full list of countries in the system, with the newest country at the bottom.

A Comprehensive Guide for building Web APIs with Flask

If the system supports multiple users the authentication credentials sent by the client could be used to obtain user specific to do lists. In such a system we would have a second resource, which would be the users. A POST request restful api python flask on the users resource would represent a new user registering for the service. A GET request would return user information back to the client. A PUT request would update the user information, maybe updating an email address.

• This tells Connexion which directory to look in for its configuration file.
• Let’s start by creating a project directory and a virtual environment.
• Flask restful defines the resource class, which contains methods for each HTTP method.
• For this example, the statement This is executed BEFORE each request.

I will explain what we changed from the original API to get it working with CORS. If you run the app locally, Flask will start a local server. This list contains three instances of Country for the initial countries in the API. Pydantic models provide some great features and allow FastAPI to easily process JSON data. FastAPI is a Python web framework that’s optimized for building APIs.

You can also view the response’s HTTP headers with response.headers. This dictionary contains metadata about the response, such as the Content-Type of the response. This code calls requests.get() to send a GET request to /todos/1, which responds with the todo item with the ID 1. Then you can call .json() on the response object to view the data that came back from the API.