Python Web Development

Flask, FastAPI, Django basics, and web application patterns.

Overview

Build web applications with Python.

Flask Basics

from flask import Flask, jsonify, request

app = Flask(__name__)

@app.route('/')
def home():
    return "Hello, World!"

@app.route('/api/users', methods=['GET'])
def get_users():
    users = [
        {"id": 1, "name": "Alice"},
        {"id": 2, "name": "Bob"}
    ]
    return jsonify(users)

@app.route('/api/users', methods=['POST'])
def create_user():
    data = request.get_json()
    return jsonify({"message": f"User {data['name']} created"}), 201

if __name__ == '__main__':
    app.run(debug=True)

FastAPI Basics

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()

class User(BaseModel):
    name: str
    email: str
    age: int

@app.get("/")
def read_root():
    return {"Hello": "World"}

@app.get("/users/{user_id}")
def read_user(user_id: int):
    return {"user_id": user_id, "name": "Alice"}

@app.post("/users/")
def create_user(user: User):
    return {"message": f"User {user.name} created"}

# Run with: uvicorn main:app --reload

Django Basics

# models.py
from django.db import models

class User(models.Model):
    name = models.CharField(max_length=100)
    email = models.EmailField(unique=True)
    created_at = models.DateTimeField(auto_now_add=True)

# views.py
from django.http import JsonResponse
from .models import User

def user_list(request):
    users = list(User.objects.values())
    return JsonResponse(users, safe=False)

Practice

Build a REST API with FastAPI for a todo application.