Python Flask RESTful API Tutorial – Simple 2024 Guide

Seeking a beginner-friendly Python Flask RESTful API tutorial? Look no further, you're in the right place!

Python Flask RESTful API Tutorial - Introduction

In this guide, I will show you exactly how to create Flask RESTful APIs with an easy-to-understand example. The example RESTful API you will create in this tutorial will allow you to add text messages to a file using an HTTP POST request, and display them with a GET request.

What is Flask?

Flask is a Python web framework that allows you to create web applications and RESTful APIs using the Python language.

What is a RESTful API?

A RESTful API (Representational State Transfer) is a set of rules that developers follow when they create their API. It's based on the idea of making requests to resources on a server, where each resource is uniquely identified by a URL (Uniform Resource Locator). In simple terms, think of it as ordering food from a menu in a restaurant. You choose what you want from the menu (the resource), place an order (send a request), and then you receive your food (get a response).

Python Flask RESTful API Tutorial - Prerequisites

To follow this tutorial you need:

• Basic knowledge of the Linux command line.
• An Ubuntu 22.04 server with a non-root user with sudo privileges. You can get affordable, and powerful Ubuntu servers from our website, and you can check out our How to access your server using SSH guide to learn how to access your server and create a sudo user.
• Basic knowledge of the Python programming language.

Step 1 - Update The Package Cache

To get the latest packages, start by updating the packages in the package manager cache to the latest available versions using the following command:

sudo apt update

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Step 2 - Installing Core Dependencies

Before you start coding your Flask RESTful API, you need to install some core dependencies for your Python programming environment. To do this, use the following command:

sudo apt install python3-pip python3-dev build-essential libssl-dev libffi-dev python3-setuptools python3-venv

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With this, you can now create a Python virtual environment for your project.

Step 3 - Isolating your Flask RESTful API in a Virtual Environment

Before you install Flask, you will first create a project folder and then create a Python virtual environment inside it to isolate your project code and dependencies from the rest of the system. Python virtual environments allow you to have multiple isolated Python environments on one computer. This is useful for projects that require different versions of Python, or for projects that you don't want to contaminate with code from other projects. This ensures that each Python project is isolated from your other projects, so that conflict between dependencies does not occur. First, create the project folder, we'll call it myapp:

mkdir myapp

Navigate to it:

cd myapp

Create a Python virtual environment inside your myapp project folder:

python3 -m venv env

Activate it:

source env/bin/activate

Your command line should now have an (env) prefix indicating that your virtual environment is activated. Install Flask:

pip install