Python | Build a REST API using Flask
Prerequisite: Introduction to Rest API
REST stands for REpresentational State Transfer and is an architectural style used in modern web development. It defines a set or rules/constraints for a web application to send and receive data.
In this article, we will build a REST API in Python using the Flask framework. Flask is a popular micro framework for building web applications. Since it is a micro-framework, it is very easy to use and lacks most of the advanced functionality which is found in a full-fledged framework. Therefore, building a REST API in Flask is very simple.
There are two ways of creating a REST API in Flask:
- Using Flask without any external libraries
- Using flask_restful library
flask_restful can be installed via the pip command:
sudo pip3 install flask-restful
Method 1: using only Flask
Here, there are two functions: One function to just return or print the data sent through GET or POST and another function to calculate the square of a number sent through GET request and print it.
Executing the square function:
Method 2: Using flask-restful
Flask Restful is an extension for Flask that adds support for building REST APIs in Python using Flask as the back-end. It encourages best practices and is very easy to set up. Flask restful is very easy to pick up if you’re already familiar with flask.
flask_restful, the main building block is a resource. Each resource can have several methods associated with it such as GET, POST, PUT, DELETE, etc. for example, there could be a resource that calculates the square of a number whenever a get request is sent to it. Each resource is a class that inherits from the Resource class of flask_restful. Once the resource is created and defined, we can add our custom resource to the api and specify a URL path for that corresponding resource.