![\"Python](\"https:\/\/www.ssdnodes.com\/wp-content\/uploads\/2024\/03\/Flask-RESTful-API-Tutorial-1.png\")
<\/p>\nSeeking a beginner-friendly Python Flask RESTful API tutorial? Look no further, you're in the right place!<\/p>\n
In this guide, I will show you exactly how to create Flask RESTful APIs with an easy-to-understand example.<\/p>\n
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.<\/p>\n
<\/p>\n
Flask is a Python web framework that allows you to create web applications and RESTful APIs using the Python language.<\/p>\n
A RESTful API<\/a> (Representational State Transfer) is a set of rules that developers follow when they create their API<\/a>. 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).<\/p>\n 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).<\/p>\n To follow this tutorial you need:<\/p>\n To get the latest packages, start by updating the packages in the package manager cache to the latest available versions using the following command:<\/p>\n 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:<\/p>\n With this, you can now create a Python virtual environment for your project.<\/p>\n 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.<\/p>\n 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.<\/p>\n First, create the project folder, we'll call it Navigate to it:<\/p>\n Create a Python virtual environment inside your Activate it:<\/p>\n Your command line should now have an Install Flask:<\/p>\n With Flask now installed, you can now create a small application.<\/p>\n First, we'll create a small Flask application that displays a In your Add the following code to it:<\/p>\n This code uses the Flask class to display an Save and close the file.<\/p>\n If you've set up a firewall using UFW, you need to allow access to port Next, run your application using the following command:<\/p>\n You will get the following output, which gives information on your application and warns you not to use this simple Flask server on a production environment:<\/p>\n You can now visit your application's web page using your server's IP address and the You'll see the To terminate the flask application, tap The first part of our Flask RESTful API involves creating a new Flask POST endpoint<\/strong> that accepts POST requests and adds a new message to a text database.<\/p>\n First, open your Add the following highlighted parts:<\/p>\n Save and close the file.<\/p>\n Here, you imported the You added the route In the If there is already a list of JSON messages in the Next, you open the Finally, you return the submitted message in a JSON format as a response with the Create the data file:<\/p>\n Then run the server:<\/p>\n Now, send a POST request with a message and a name using Remember to change You should receive the following response:<\/p>\n You can use the same command to add more messages:<\/p>\n Now that you've added a few messages using a POST request, you will create a route to display all the messages in your database using a GET request next.<\/p>\n Now that you have a method for adding new messages, the second part of our Flask RESTful API involves creating a new Flask GET endpoint<\/strong> that accepts GET requests and displays messages in a JSON format.<\/p>\n To display the messages in the You should see the following output:<\/p>\n Now, you can create a new route in your First, open Add the following route before the Save and close the file.<\/p>\n Here, you use the Now, you can test this new route using You should receive the messages you previously added to your database as a JSON response:<\/p>\n With this, you now have a small RESTful API that can be used to add and retrieve messages.<\/p>\n This was a simple demonstration of how to create a RESTful API with Flask, in which you used a simple JSON file as a database. However, using a JSON file as a database in the real world is extremely inefficient and cumbersome. Therefore, you need to use an SQL or NoSQL database instead such as SQLite, PostgreSQL, or MongoDB.<\/p>\n In this tutorial, you've learned how to create a simple RESTful API with Flask in Python. You built a RESTful API that receives data via POST requests, and gets data using GET requests.<\/p>\n Here are some best practices for developing RESTful APIs in Flask:<\/p>\n Flask offers simplicity and flexibility, allowing developers to build lightweight APIs quickly, whereas other frameworks might be more opinionated or complex.<\/p>\n Yes, Flask can be used to build large-scale, production-ready RESTful APIs when combined with best practices such as modular code organization, efficient database management, and robust testing. By following industry standards and leveraging Flask's extensibility, you can create scalable and reliable APIs that meet the demands of your application's users.<\/p>\n","protected":false},"excerpt":{"rendered":" Master Flask RESTful APIs: Beginner-friendly tutorial series for building, testing, & deploying your own API step-by-step. Unleash Python power with Flask!<\/p>\n","protected":false},"author":19,"featured_media":8841,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"categories":[18,30],"tags":[],"class_list":["post-7453","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-devops","category-tutorials"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.ssdnodes.com\/wp-json\/wp\/v2\/posts\/7453","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ssdnodes.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ssdnodes.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ssdnodes.com\/wp-json\/wp\/v2\/users\/19"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ssdnodes.com\/wp-json\/wp\/v2\/comments?post=7453"}],"version-history":[{"count":19,"href":"https:\/\/www.ssdnodes.com\/wp-json\/wp\/v2\/posts\/7453\/revisions"}],"predecessor-version":[{"id":13051,"href":"https:\/\/www.ssdnodes.com\/wp-json\/wp\/v2\/posts\/7453\/revisions\/13051"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ssdnodes.com\/wp-json\/wp\/v2\/media\/8841"}],"wp:attachment":[{"href":"https:\/\/www.ssdnodes.com\/wp-json\/wp\/v2\/media?parent=7453"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ssdnodes.com\/wp-json\/wp\/v2\/categories?post=7453"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ssdnodes.com\/wp-json\/wp\/v2\/tags?post=7453"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Python Flask RESTful API Tutorial - Prerequisites<\/h2>\n
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sudo<\/code> privileges. You can get affordable, and powerful Ubuntu servers from our website<\/a>, and you can check out our How to access your server using SSH<\/a> guide to learn how to access your server and create a sudo<\/code> user.<\/li>\nStep 1 - Update The Package Cache<\/h2>\n
sudo apt update<\/code><\/pre>\nOutput<\/h3>\n
![\"Flask](\"https:\/\/www.ssdnodes.com\/wp-content\/uploads\/2024\/03\/sudo-apt-update-1.png\")
<\/p>\nStep 2 - Installing Core Dependencies<\/h2>\n
sudo apt install python3-pip python3-dev build-essential libssl-dev libffi-dev python3-setuptools python3-venv<\/code><\/pre>\nOutput<\/h3>\n
![\"Python](\"https:\/\/www.ssdnodes.com\/wp-content\/uploads\/2024\/03\/install-deps-1.png\")
<\/p>\nStep 3 - Isolating your Flask RESTful API in a Virtual Environment<\/h2>\n
myapp<\/code>:<\/p>\nmkdir myapp<\/code><\/pre>\ncd myapp<\/code><\/pre>\nmyapp<\/code> project folder:<\/p>\npython3 -m venv env<\/code><\/pre>\nsource env\/bin\/activate<\/code><\/pre>\n(env)<\/code> prefix indicating that your virtual environment is activated.<\/p>\npip install flask<\/code><\/pre>\nOutput<\/h3>\n
![\"Python](\"https:\/\/www.ssdnodes.com\/wp-content\/uploads\/2024\/03\/flask-install-success-1.png\")
<\/p>\nStep 4 - Building a Small Flask Application to Test Our Installation<\/h2>\n
Hello World!<\/code> web page using a single Python file to test that everything works.<\/p>\nmyapp<\/code> folder, open a file called app.py<\/code>:<\/p>\nnano app.py<\/code><\/pre>\nfrom flask import Flask\r\napp = Flask(__name__)\r\n\r\n@app.route('\/')\r\ndef hello():\r\n return '<h1>Hello World! This is my Flask Application!<\/h1>'\r\n\r\nif __name__ == \"__main__\":\r\n app.run(host='0.0.0.0')<\/code><\/pre>\nH1<\/code> heading on the main route (\/<\/code>).<\/p>\n5000<\/code>, which is the port Flask uses:<\/p>\nsudo ufw allow 5000<\/code><\/pre>\npython app.py<\/code><\/pre>\n![\"Flask](\"https:\/\/www.ssdnodes.com\/wp-content\/uploads\/2024\/03\/app-run-output-1.png\")
<\/p>\n5000<\/code> port. Use your browser and navigate to the following URL:<\/p>\nhttp:\/\/your_server_ip:5000<\/code><\/pre>\nHello World! This is my Flask Application!<\/code> header on your browser.<\/p>\nCTRL-C<\/code> in your terminal to stop the Flask development server.<\/p>\nStep 5 - Creating a Flask POST Endpoint for the RESTful API<\/h2>\n
app.py<\/code> file for modification:<\/p>\nnano app.py<\/code><\/pre>\nimport json\r\nfrom flask import Flask, request, jsonify<\/mark>\r\napp = Flask(__name__)\r\n\r\n@app.route('\/')\r\ndef hello():\r\n return '<h1>Hello World! This is my Flask Application!<\/h1>'\r\n\r\n\r\n@app.post('\/api\/')\r\ndef add_message():\r\n message = json.loads(request.data)\r\n with open('data.json', 'r') as f:\r\n data = f.read()\r\n\r\n # If no data is in the text file, create a new list\r\n if not data:\r\n messages = [message]\r\n # If data exists in the text file, load it into a list\r\n # then append the new message to it\r\n else:\r\n messages = json.loads(data)\r\n messages.append(message)\r\n\r\n with open('data.json', 'w') as f:\r\n f.write(json.dumps(messages, indent=2))\r\n\r\n # return the added message\r\n return jsonify(message), 201\r\n<\/mark>\r\nif __name__ == \"__main__\":\r\n app.run(host='0.0.0.0')<\/code><\/pre>\njson<\/code> Python module, and the request<\/code> and jsonify<\/code> helpers from the Flask package.<\/p>\n@app.post('\/api\/')<\/code> which accepts POST requests, hence why you use the @app.post<\/code> decorator instead of the standard @app.route()<\/code>.<\/p>\nadd_message()<\/code> view function, you use json.loads()<\/code> to load the POST request data as JSON into a variable called message<\/code>, then you open a file called data.json<\/code> and read it and save its contents in the data<\/code> variable. For now, the data.json<\/code> file does not exist yet, but you will create it later. If data.json<\/code> is empty, you create a messages<\/code> list with the POST request data that's in the message<\/code> variable.<\/p>\ndata.json<\/code> file, you load it into the messages<\/code> variable, and then append the new message in the POST request to it.<\/p>\ndata.json<\/code> file for writing, and then you write the messages into it.<\/p>\n201<\/code> HTTP status which indicates that the request succeeded, and a new resource was created as a result.<\/p>\ntouch data.json<\/code><\/pre>\npython app.py<\/code><\/pre>\ncurl<\/code>:<\/p>\ncurl -X POST -d '{\"name\":\"mike\", \"message\": \"Hello there!\"}' http:\/\/your_IP:5000\/api\/ -H \"Content-Type: application\/json\"<\/code><\/pre>\nyour_IP<\/code> to your server's IP address.<\/p>\n![\"Flask](\"https:\/\/www.ssdnodes.com\/wp-content\/uploads\/2024\/03\/json-response-1.png\")
<\/p>\ncurl -X POST -d '{\"name\":\"john\", \"message\": \"Hello Everyone! My name is John!\"}' http:\/\/your_IP:5000\/api\/ -H \"Content-Type: application\/json\"<\/code><\/pre>\nStep 6 - Creating a Flask GET Endpoint for the RESTful API<\/h2>\n
data.json<\/code> file, you can simply use cat<\/code> to read the file:<\/p>\ncat data.json<\/code><\/pre>\n![\"Flask](\"https:\/\/www.ssdnodes.com\/wp-content\/uploads\/2024\/03\/GET-output-1.png\")
<\/p>\napp.py<\/code> file that returns the contents of your data.json<\/code> database file as a JSON response.<\/p>\napp.py<\/code> for modification:<\/p>\nnano app.py<\/code><\/pre>\nif __name__ == \"__main__\":<\/code> line of your app.py<\/code> file:<\/p>\n@app.get('\/api\/')\r\ndef display_messages():\r\n with open('data.json', 'r') as f:\r\n data = f.read()\r\n if not data:\r\n return jsonify({'error': 'data not found'}), 404\r\n messages = json.loads(data)\r\n\r\n return jsonify(messages)<\/code><\/pre>\n@app.get()<\/code> decorator to respond to GET requests that are sent to the \/api\/<\/code> route. In the display_messages()<\/code> view function, you open the data.json<\/code> and read it, if it's empty, you return an error message as a JSON response indicating that the data was not found along with a 404<\/code> HTTP status code. Otherwise you load the data into the messages<\/code> variable and return it as a response.<\/p>\ncurl<\/code> by sending a GET request to the \/api\/<\/code> route:<\/p>\ncurl http:\/\/your_IP:5000\/api\/<\/code><\/pre>\n![\"Flask](\"https:\/\/www.ssdnodes.com\/wp-content\/uploads\/2024\/03\/curl-get-output-1.png\")
<\/p>\nNote<\/h2>\n
Conclusion<\/h2>\n
FAQ: Questions on Python Flask RESTful APIs<\/h2>\n
What are some best practices for designing and developing Flask RESTful APIs?<\/h3>\n
\n
How does Flask differ from other frameworks for building RESTful APIs?<\/h3>\n
Is Flask suitable for building large-scale production-ready RESTful APIs?<\/h3>\n