Though, as mentioned, we will use marshmallow to serialize and deserialize entities through our endpoints. REST API services let you restful api python flask interact with the database by simply doing HTTP requests. In this article you learn how to write a REST server using the Flask.
Each of the endpoints above performs a different action based on the HTTP method. You can specify a function that should always execute before the request is processed by using app.before_request decorator. However, if noticed correctly, the welcome decorator has a trailing slash while the goodbye decorator does not have any. If we send requests, we can expect two behaviors out of these two. This is how we usually deal with passing data and information with responses.
HTTP status codes come in handy when working with REST APIs as you’ll often need to perform different logic based on the results of the request. A REST API client application can use these five HTTP methods to manage the state of resources in the web service. Many web services, like YouTube and GitHub, make their data accessible to third-party applications through an application programming interface (API). One of the most popular ways to build APIs is the REST architecture style.
In its place, we defined an endpoint to handle HTTP GET requests to return incomes and another endpoint to handle HTTP POST requests to add new ones. These endpoints are annotated with @app.route to define routes listening to requests on the /incomes endpoint. Flask provides great documentation on what exactly this does. Now that we have created the class and binded the endpoint, the next step is to write the individual methods to read, write, update or delete data from the CSV file. In order to read data from the CSV file, we are going to use another library Pandas, which will make our life easier to deal with data from flat files. You can read more about
Pandas from my Getting started with Pandas in Python article.
Next, you call requests.put() with new JSON data to replace the existing to-do’s values. Successful PUT requests will always return 200 instead of 201 because you aren’t creating a new resource but just updating an existing one. REST APIs listen for HTTP methods like GET, POST, and DELETE to know which operations to perform on the web service’s resources. A resource is any data available in the web service that can be accessed and manipulated with HTTP requests to the REST API. The HTTP method tells the API which action to perform on the resource.
In this section, you’ll look at some recommended steps to follow as you build an API. The requests library is an awesome tool for working with REST APIs and an indispensable part of your Python tool belt. In the next section, you’ll change gears and consider what it takes to build a REST API.
The commands are slightly different if you use the Windows native version of Python. This JSON object resembles the Person component that you were defining earlier in swagger.yml and that you’re referencing with $ref in schema. Also, just like each new Python version includes new features, there may be keywords added or deprecated in the OpenAPI specification. Flask comes with the Jinja Templating Engine, which enables you to enhance your templates.
Additionally, Connexion uses swagger.yml to create API documentation for you. You then define the PEOPLE dictionary data structure in line 8, which is the data you’ll work with in this part of the tutorial series. In line 7, you tell the app instance to read the swagger.yml file from the specification directory and configure the system to provide the Connexion functionality. After you navigate to the project folder, it’s a good idea to create and activate a virtual environment. That way, you’re installing any project dependencies not system-wide but only in your project’s virtual environment.
Flask Restful is an extension for Flask that adds support for building REST APIs in Python using Flask as the back-end. Flask restful is very easy to pick up if you’re already familiar with flask. In the swagger.yml file, you configured Connexion with the operationId value “people.read_all”. So, when the API gets an HTTP request for GET /api/people, your Flask app calls a read_all() function within a people module. With the specifications that you include in swagger.yml, you define what data your web server can expect and how your server should respond to requests. But so far, your Flask project doesn’t know about your swagger.yml file.