Building a REST API in Python is a fundamental skill for developers. In this step-by-step guide, we’ll explore the Flask framework to create a robust REST API. Follow along to understand the essentials of API development, from setting up endpoints to handling requests, and witness it in action with a hands-on example.
Understanding REST and Flask Basics
REST (Representational State Transfer) is an architectural style for designing networked applications. Flask, a lightweight and versatile web framework, is an excellent choice for building REST APIs in Python.
Setting Up Flask
Install Flask using pip:
pip install Flask
Create a file named app.py for your Flask application.
Creating Endpoints
Define routes and endpoints to handle different requests. For simplicity, let’s create an endpoint that returns a list of items.
from flask import Flask, jsonify
app = Flask(__name__)
@app.route('/api/items', methods=['GET'])
def get_items():
items = ['item1', 'item2', 'item3']
return jsonify({'items': items})
if __name__ == '__main__':
app.run(debug=True)Running the Flask Application
Run the Flask application:
python app.py
Visit http://localhost:5000/api/items in your browser or use a tool like curl to test the endpoint:
curl http://localhost:5000/api/items
Handling Requests and Responses
Flask simplifies request handling. Access request data, parse JSON, and send responses effortlessly.
from flask import Flask, jsonify, request
app = Flask(__name__)
@app.route('/api/greet', methods=['POST'])
def greet_user():
data = request.get_json()
name = data.get('name', 'Guest')
greeting = f"Hello, {name}!"
return jsonify({'greeting': greeting})
if __name__ == '__main__':
app.run(debug=True)Test the new endpoint:
curl -X POST -H "Content-Type: application/json" -d '{"name": "Sachin"}' http://localhost:5000/api/greet
Todo API
Create a simple Todo API with endpoints for listing, creating, and deleting tasks. Define routes and use a list to store tasks.
from flask import Flask, jsonify, request
app = Flask(__name__)
tasks = []
@app.route('/api/tasks', methods=['GET'])
def get_tasks():
return jsonify({'tasks': tasks})
@app.route('/api/tasks', methods=['POST'])
def create_task():
data = request.get_json()
task = {'id': len(tasks) + 1, 'title': data.get('title', ''), 'done': False}
tasks.append(task)
return jsonify({'task': task}), 201
@app.route('/api/tasks/<int:task_id>', methods=['DELETE'])
def delete_task(task_id):
task = next((t for t in tasks if t['id'] == task_id), None)
if task:
tasks.remove(task)
return jsonify({'result': True})
else:
return jsonify({'result': False, 'message': 'Task not found'}), 404
if __name__ == '__main__':
app.run(debug=True)Test the Todo API with various requests to /api/tasks.
