Working with APIs

Introduction

Learn to build and consume REST APIs using Flask and other frameworks.

Flask Basics

from flask import Flask, jsonify, request

app = Flask(__name__)

@app.route("/api/hello")
def hello():
    return jsonify({"message": "Hello, World!"})

@app.route("/api/users/<int:user_id>")
def get_user(user_id):
    return jsonify({"id": user_id, "name": "Alice"})

@app.route("/api/users", methods=["POST"])
def create_user():
    data = request.json
    return jsonify({"id": 1, **data}), 201

API Error Handling

from flask import abort

@app.route("/api/users/<int:user_id>")
def get_user(user_id):
    user = find_user(user_id)
    if not user:
        abort(404, description="User not found")
    return jsonify(user)

RESTful Design

# Resource-based endpoints
# GET    /users      - List users
# POST   /users      - Create user
# GET    /users/1    - Get user 1
# PUT    /users/1    - Update user 1
# DELETE /users/1    - Delete user 1

Practice Problems

1. Build API for blog posts (CRUD)
2. Add authentication middleware
3. Implement request validation
4. Create pagination endpoint
5. Add rate limiting to API